Update v8.13.2edit

This section lists all updates associated with version 8.13.2 of the Fleet integration Prebuilt Security Detection Rules.

Rule Description Status Version

Network Connection from Binary with RWX Memory Region

Monitors for the execution of a unix binary with read, write and execute memory region permissions, followed by a network connection. The mprotect() system call is used to change the access protections on a region of memory that has already been allocated. This syscall allows a process to modify the permissions of pages in its virtual address space, enabling or disabling permissions such as read, write, and execute for those pages. RWX permissions on memory is in many cases overly permissive, and should (especially in conjunction with an outbound network connection) be analyzed thoroughly.

new

1

Unknown Execution of Binary with RWX Memory Region

Monitors for the execution of a previously unknown unix binary with read, write and execute memory region permissions. The mprotect() system call is used to change the access protections on a region of memory that has already been allocated. This syscall allows a process to modify the permissions of pages in its virtual address space, enabling or disabling permissions such as read, write, and execute for those pages. RWX permissions on memory is in many cases overly permissive, and should be analyzed thoroughly.

new

1

PowerShell Script with Veeam Credential Access Capabilities

Identifies PowerShell scripts that can access and decrypt Veeam credentials stored in MSSQL databases. Attackers can use Veeam Credentials to target backups as part of destructive operations such as Ransomware attacks.

new

1

Veeam Backup Library Loaded by Unusual Process

Identifies potential credential decrypt operations by PowerShell or unsigned processes using the Veeam.Backup.Common.dll library. Attackers can use Veeam Credentials to target backups as part of destructive operations such as Ransomware attacks.

new

1

Potential Veeam Credential Access Command

Identifies commands that can access and decrypt Veeam credentials stored in MSSQL databases. Attackers can use Veeam Credentials to target backups as part of destructive operations such as Ransomware attacks.

new

1

Potential Cookies Theft via Browser Debugging

Identifies the execution of a Chromium based browser with the debugging process argument, which may indicate an attempt to steal authentication cookies. An adversary may steal web application or service session cookies and use them to gain access web applications or Internet services as an authenticated user without needing credentials.

update

105

WebServer Access Logs Deleted

Identifies the deletion of WebServer access logs. This may indicate an attempt to evade detection or destroy forensic evidence on a system.

update

105

Tampering of Shell Command-Line History

Adversaries may attempt to clear or disable the Bash command-line history in an attempt to evade detection or forensic investigations.

update

105

Elastic Agent Service Terminated

Identifies the Elastic endpoint agent has stopped and is no longer running on the host. Adversaries may attempt to disable security monitoring tools in an attempt to evade detection or prevention capabilities during an intrusion. This may also indicate an issue with the agent itself and should be addressed to ensure defensive measures are back in a stable state.

update

106

Masquerading Space After Filename

This rules identifies a process created from an executable with a space appended to the end of the filename. This may indicate an attempt to masquerade a malicious file as benign to gain user execution. When a space is added to the end of certain files, the OS will execute the file according to it’s true filetype instead of it’s extension. Adversaries can hide a program’s true filetype by changing the extension of the file. They can then add a space to the end of the name so that the OS automatically executes the file when it’s double-clicked.

update

6

Timestomping using Touch Command

Timestomping is an anti-forensics technique which is used to modify the timestamps of a file, often to mimic files that are in the same folder.

update

106

Security Software Discovery via Grep

Identifies the use of the grep command to discover known third-party macOS and Linux security tools, such as Antivirus or Host Firewall details.

update

109

Virtual Machine Fingerprinting via Grep

An adversary may attempt to get detailed information about the operating system and hardware. This rule identifies common locations used to discover virtual machine hardware by a non-root user. This technique has been used by the Pupy RAT and other malware.

update

105

Potential Reverse Shell Activity via Terminal

Identifies the execution of a shell process with suspicious arguments which may be indicative of reverse shell activity.

update

108

Suspicious JAVA Child Process

Identifies suspicious child processes of the Java interpreter process. This may indicate an attempt to execute a malicious JAR file or an exploitation attempt via a JAVA specific vulnerability.

update

208

My First Rule

This rule helps you test and practice using alerts with Elastic Security as you get set up. It’s not a sign of threat activity.

update

3

Hosts File Modified

The hosts file on endpoints is used to control manual IP address to hostname resolutions. The hosts file is the first point of lookup for DNS hostname resolution so if adversaries can modify the endpoint hosts file, they can route traffic to malicious infrastructure. This rule detects modifications to the hosts file on Microsoft Windows, Linux (Ubuntu or RHEL) and macOS systems.

update

108

Zoom Meeting with no Passcode

This rule identifies Zoom meetings that are created without a passcode. Meetings without a passcode are susceptible to Zoombombing. Zoombombing is carried out by taking advantage of Zoom sessions that are not protected with a passcode. Zoombombing refers to the unwanted, disruptive intrusion, generally by Internet trolls and hackers, into a video conference call. In a typical Zoombombing incident, a teleconferencing session is hijacked by the insertion of material that is lewd, obscene, racist, or antisemitic in nature, typically resulting of the shutdown of the session.

update

103

Deprecated - Remote File Creation on a Sensitive Directory

Discovery of files created by a remote host on sensitive directories and folders. Remote file creation in these directories could indicate a malicious binary or script trying to compromise the system.

update

2

SSH Authorized Keys File Modification

The Secure Shell (SSH) authorized_keys file specifies which users are allowed to log into a server using public key authentication. Adversaries may modify it to maintain persistence on a victim host by adding their own public key(s).

update

205

Threat Intel IP Address Indicator Match

This rule is triggered when an IP address indicator from the Threat Intel Filebeat module or integrations has a match against a network event.

update

6

Threat Intel Hash Indicator Match

This rule is triggered when a hash indicator from the Threat Intel Filebeat module or integrations has a match against an event that contains file hashes, such as antivirus alerts, process creation, library load, and file operation events.

update

7

Threat Intel Windows Registry Indicator Match

This rule is triggered when a Windows registry indicator from the Threat Intel Filebeat module or integrations has a match against an event that contains registry data.

update

6

Threat Intel URL Indicator Match

This rule is triggered when a URL indicator from the Threat Intel Filebeat module or integrations has a match against an event that contains URL data, like DNS events, network logs, etc.

update

6

First Time Seen AWS Secret Value Accessed in Secrets Manager

An adversary with access to a compromised AWS service such as an EC2 instance, Lambda function, or other service may attempt to leverage the compromised service to access secrets in AWS Secrets Manager. This rule looks for the first time a specific user identity has programmatically retrieved a specific secret value from Secrets Manager using the GetSecretValue action. This rule assumes that AWS services such as Lambda functions and EC2 instances are setup with IAM role’s assigned that have the necessary permissions to access the secrets in Secrets Manager. An adversary with access to a compromised AWS service such as an EC2 instance, Lambda function, or other service would rely on the compromised service’s IAM role to access the secrets in Secrets Manager.

update

309

AWS Route Table Created

Identifies when an AWS Route Table has been created.

update

206

AWS Route Table Modified or Deleted

Identifies when an AWS Route Table has been modified or deleted.

update

206

Statistical Model Detected C2 Beaconing Activity

A statistical model has identified command-and-control (C2) beaconing activity. Beaconing can help attackers maintain stealthy communication with their C2 servers, receive instructions and payloads, exfiltrate data and maintain persistence in a network.

update

4

Statistical Model Detected C2 Beaconing Activity with High Confidence

A statistical model has identified command-and-control (C2) beaconing activity with high confidence. Beaconing can help attackers maintain stealthy communication with their C2 servers, receive instructions and payloads, exfiltrate data and maintain persistence in a network.

update

4

Potential Data Exfiltration Activity to an Unusual ISO Code

A machine learning job has detected data exfiltration to a particular geo-location (by region name). Data transfers to geo-locations that are outside the normal traffic patterns of an organization could indicate exfiltration over command and control channels.

update

3

Potential Data Exfiltration Activity to an Unusual IP Address

A machine learning job has detected data exfiltration to a particular geo-location (by IP address). Data transfers to geo-locations that are outside the normal traffic patterns of an organization could indicate exfiltration over command and control channels.

update

3

Potential Data Exfiltration Activity to an Unusual Destination Port

A machine learning job has detected data exfiltration to a particular destination port. Data transfer patterns that are outside the normal traffic patterns of an organization could indicate exfiltration over command and control channels.

update

3

Potential Data Exfiltration Activity to an Unusual Region

A machine learning job has detected data exfiltration to a particular geo-location (by region name). Data transfers to geo-locations that are outside the normal traffic patterns of an organization could indicate exfiltration over command and control channels.

update

3

Spike in Bytes Sent to an External Device

A machine learning job has detected high bytes of data written to an external device. In a typical operational setting, there is usually a predictable pattern or a certain range of data that is written to external devices. An unusually large amount of data being written is anomalous and can signal illicit data copying or transfer activities.

update

3

Spike in Bytes Sent to an External Device via Airdrop

A machine learning job has detected high bytes of data written to an external device via Airdrop. In a typical operational setting, there is usually a predictable pattern or a certain range of data that is written to external devices. An unusually large amount of data being written is anomalous and can signal illicit data copying or transfer activities.

update

3

Unusual Process Writing Data to an External Device

A machine learning job has detected a rare process writing data to an external device. Malicious actors often use benign-looking processes to mask their data exfiltration activities. The discovery of such a process that has no legitimate reason to write data to external devices can indicate exfiltration.

update

3

Machine Learning Detected DGA activity using a known SUNBURST DNS domain

A supervised machine learning model has identified a DNS question name that used by the SUNBURST malware and is predicted to be the result of a Domain Generation Algorithm.

update

3

Potential DGA Activity

A population analysis machine learning job detected potential DGA (domain generation algorithm) activity. Such activity is often used by malware command and control (C2) channels. This machine learning job looks for a source IP address making DNS requests that have an aggregate high probability of being DGA activity.

update

3

Machine Learning Detected a DNS Request With a High DGA Probability Score

A supervised machine learning model has identified a DNS question name with a high probability of sourcing from a Domain Generation Algorithm (DGA), which could indicate command and control network activity.

update

3

Machine Learning Detected a DNS Request Predicted to be a DGA Domain

A supervised machine learning model has identified a DNS question name that is predicted to be the result of a Domain Generation Algorithm (DGA), which could indicate command and control network activity.

update

3

High Mean of Process Arguments in an RDP Session

A machine learning job has detected unusually high number of process arguments in an RDP session. Executing sophisticated attacks such as lateral movement can involve the use of complex commands, obfuscation mechanisms, redirection and piping, which in turn increases the number of arguments in a command.

update

3

High Mean of RDP Session Duration

A machine learning job has detected unusually high mean of RDP session duration. Long RDP sessions can be used to evade detection mechanisms via session persistence, and might be used to perform tasks such as lateral movement, that might require uninterrupted access to a compromised machine.

update

3

Unusual Remote File Size

A machine learning job has detected an unusually high file size shared by a remote host indicating potential lateral movement activity. One of the primary goals of attackers after gaining access to a network is to locate and exfiltrate valuable information. Instead of multiple small transfers that can raise alarms, attackers might choose to bundle data into a single large file transfer.

update

3

High Variance in RDP Session Duration

A machine learning job has detected unusually high variance of RDP session duration. Long RDP sessions can be used to evade detection mechanisms via session persistence, and might be used to perform tasks such as lateral movement, that might require uninterrupted access to a compromised machine.

update

3

Unusual Remote File Directory

An anomaly detection job has detected a remote file transfer on an unusual directory indicating a potential lateral movement activity on the host. Many Security solutions monitor well-known directories for suspicious activities, so attackers might use less common directories to bypass monitoring.

update

3

Unusual Remote File Extension

An anomaly detection job has detected a remote file transfer with a rare extension, which could indicate potential lateral movement activity on the host.

update

3

Spike in Number of Connections Made from a Source IP

A machine learning job has detected a high count of destination IPs establishing an RDP connection with a single source IP. Once an attacker has gained access to one system, they might attempt to access more in the network in search of valuable assets, data, or further access points.

update

3

Spike in Number of Connections Made to a Destination IP

A machine learning job has detected a high count of source IPs establishing an RDP connection with a single destination IP. Attackers might use multiple compromised systems to attack a target to ensure redundancy in case a source IP gets detected and blocked.

update

3

Spike in Number of Processes in an RDP Session

A machine learning job has detected unusually high number of processes started in a single RDP session. Executing a large number of processes remotely on other machines can be an indicator of lateral movement activity.

update

3

Spike in Remote File Transfers

A machine learning job has detected an abnormal volume of remote files shared on the host indicating potential lateral movement activity. One of the primary goals of attackers after gaining access to a network is to locate and exfiltrate valuable information. Attackers might perform multiple small transfers to match normal egress activity in the network, to evade detection.

update

3

Unusual Time or Day for an RDP Session

A machine learning job has detected an RDP session started at an usual time or weekday. An RDP session at an unusual time could be followed by other suspicious activities, so catching this is a good first step in detecting a larger attack.

update

3

Potential Okta MFA Bombing via Push Notifications

Detects when an attacker abuses the Multi-Factor authentication mechanism by repeatedly issuing login requests until the user eventually accepts the Okta push notification. An adversary may attempt to bypass the Okta MFA policies configured for an organization to obtain unauthorized access.

update

3

Unusual Process Spawned by a Host

A machine learning job has detected a suspicious Windows process. This process has been classified as suspicious in two ways. It was predicted to be suspicious by the ProblemChild supervised ML model, and it was found to be an unusual process, on a host that does not commonly manifest malicious activity. Such a process may be an instance of suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

update

3

Unusual Process Spawned by a Parent Process

A machine learning job has detected a suspicious Windows process. This process has been classified as malicious in two ways. It was predicted to be malicious by the ProblemChild supervised ML model, and it was found to be an unusual child process name, for the parent process, by an unsupervised ML model. Such a process may be an instance of suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

update

3

Unusual Process Spawned by a User

A machine learning job has detected a suspicious Windows process. This process has been classified as malicious in two ways. It was predicted to be malicious by the ProblemChild supervised ML model, and it was found to be suspicious given that its user context is unusual and does not commonly manifest malicious activity,by an unsupervised ML model. Such a process may be an instance of suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

update

3

Machine Learning Detected a Suspicious Windows Event Predicted to be Malicious Activity

A supervised machine learning model (ProblemChild) has identified a suspicious Windows process event with high probability of it being malicious activity. Alternatively, the model’s blocklist identified the event as being malicious.

update

3

Machine Learning Detected a Suspicious Windows Event with a High Malicious Probability Score

A supervised machine learning model (ProblemChild) has identified a suspicious Windows process event with high probability of it being malicious activity. Alternatively, the model’s blocklist identified the event as being malicious.

update

3

Suspicious Windows Process Cluster Spawned by a Host

A machine learning job combination has detected a set of one or more suspicious Windows processes with unusually high scores for malicious probability. These process(es) have been classified as malicious in several ways. The process(es) were predicted to be malicious by the ProblemChild supervised ML model. If the anomaly contains a cluster of suspicious processes, each process has the same host name, and the aggregate score of the event cluster was calculated to be unusually high by an unsupervised ML model. Such a cluster often contains suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

update

3

Suspicious Windows Process Cluster Spawned by a Parent Process

A machine learning job combination has detected a set of one or more suspicious Windows processes with unusually high scores for malicious probability. These process(es) have been classified as malicious in several ways. The process(es) were predicted to be malicious by the ProblemChild supervised ML model. If the anomaly contains a cluster of suspicious processes, each process has the same parent process name, and the aggregate score of the event cluster was calculated to be unusually high by an unsupervised ML model. Such a cluster often contains suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

update

3

Suspicious Windows Process Cluster Spawned by a User

A machine learning job combination has detected a set of one or more suspicious Windows processes with unusually high scores for malicious probability. These process(es) have been classified as malicious in several ways. The process(es) were predicted to be malicious by the ProblemChild supervised ML model. If the anomaly contains a cluster of suspicious processes, each process has the same user name, and the aggregate score of the event cluster was calculated to be unusually high by an unsupervised ML model. Such a cluster often contains suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

update

3

Network Activity Detected via cat

This rule monitors for the execution of the cat command, followed by a connection attempt by the same process. Cat is capable of transfering data via tcp/udp channels by redirecting its read output to a /dev/tcp or /dev/udp channel. This activity is highly suspicious, and should be investigated. Attackers may leverage this capability to transfer tools or files to another host in the network or exfiltrate data while attempting to evade detection in the process.

update

6

Potential Protocol Tunneling via Chisel Client

This rule monitors for common command line flags leveraged by the Chisel client utility followed by a connection attempt. Chisel is a command-line utility used for creating and managing TCP and UDP tunnels, enabling port forwarding and secure communication between machines. Attackers can abuse the Chisel utility to establish covert communication channels, bypass network restrictions, and carry out malicious activities by creating tunnels that allow unauthorized access to internal systems.

update

5

Potential Protocol Tunneling via Chisel Server

This rule monitors for common command line flags leveraged by the Chisel server utility followed by a received connection within a timespan of 1 minute. Chisel is a command-line utility used for creating and managing TCP and UDP tunnels, enabling port forwarding and secure communication between machines. Attackers can abuse the Chisel utility to establish covert communication channels, bypass network restrictions, and carry out malicious activities by creating tunnels that allow unauthorized access to internal systems.

update

6

Network Activity Detected via Kworker

This rule monitors for network connections from a kworker process. kworker, or kernel worker, processes are part of the kernel’s workqueue mechanism. They are responsible for executing work that has been scheduled to be done in kernel space, which might include tasks like handling interrupts, background activities, and other kernel-related tasks. Attackers may attempt to evade detection by masquerading as a kernel worker process.

update

3

ProxyChains Activity

This rule monitors for the execution of the ProxyChains utility. ProxyChains is a command-line tool that enables the routing of network connections through intermediary proxies, enhancing anonymity and enabling access to restricted resources. Attackers can exploit the ProxyChains utility to hide their true source IP address, evade detection, and perform malicious activities through a chain of proxy servers, potentially masking their identity and intentions.

update

4

Suspicious Utility Launched via ProxyChains

This rule monitors for the execution of suspicious linux tools through ProxyChains. ProxyChains is a command-line tool that enables the routing of network connections through intermediary proxies, enhancing anonymity and enabling access to restricted resources. Attackers can exploit the ProxyChains utility to hide their true source IP address, evade detection, and perform malicious activities through a chain of proxy servers, potentially masking their identity and intentions.

update

7

Potential Linux Tunneling and/or Port Forwarding

This rule monitors for a set of Linux utilities that can be used for tunneling and port forwarding. Attackers can leverage tunneling and port forwarding techniques to bypass network defenses, establish hidden communication channels, and gain unauthorized access to internal resources, facilitating data exfiltration, lateral movement, and remote control.

update

6

Suspicious Network Activity to the Internet by Previously Unknown Executable

This rule monitors for network connectivity to the internet from a previously unknown executable located in a suspicious directory to a previously unknown destination ip. An alert from this rule can indicate the presence of potentially malicious activity, such as the execution of unauthorized or suspicious processes attempting to establish connections to unknown or suspicious destinations such as a command and control server. Detecting and investigating such behavior can help identify and mitigate potential security threats, protecting the system and its data from potential compromise.

update

8

Potential Protocol Tunneling via EarthWorm

Identifies the execution of the EarthWorm tunneler. Adversaries may tunnel network communications to and from a victim system within a separate protocol to avoid detection and network filtering, or to enable access to otherwise unreachable systems.

update

110

Sensitive Files Compression

Identifies the use of a compression utility to collect known files containing sensitive information, such as credentials and system configurations.

update

208

Potential Linux Credential Dumping via Unshadow

Identifies the execution of the unshadow utility which is part of John the Ripper, a password-cracking tool on the host machine. Malicious actors can use the utility to retrieve the combined contents of the /etc/shadow and /etc/password files. Using the combined file generated from the utility, the malicious threat actors can use them as input for password-cracking utilities or prepare themselves for future operations by gathering credential information of the victim.

update

8

Linux init (PID 1) Secret Dump via GDB

This rule monitors for the potential memory dump of the init process (PID 1) through gdb. Attackers may leverage memory dumping techniques to attempt secret extraction from privileged processes. Tools that display this behavior include "truffleproc" and "bash-memory-dump". This behavior should not happen by default, and should be investigated thoroughly.

update

6

Linux Process Hooking via GDB

This rule monitors for potential memory dumping through gdb. Attackers may leverage memory dumping techniques to attempt secret extraction from privileged processes. Tools that display this behavior include "truffleproc" and "bash-memory-dump". This behavior should not happen by default, and should be investigated thoroughly.

update

3

Potential Linux Local Account Brute Force Detected

Identifies multiple consecutive login attempts executed by one process targeting a local linux user account within a short time interval. Adversaries might brute force login attempts across different users with a default wordlist or a set of customly crafted passwords in an attempt to gain access to these accounts.

update

6

Potential External Linux SSH Brute Force Detected

Identifies multiple external consecutive login failures targeting a user account from the same source address within a short time interval. Adversaries will often brute force login attempts across multiple users with a common or known password, in an attempt to gain access to these accounts.

update

6

Potential Internal Linux SSH Brute Force Detected

Identifies multiple internal consecutive login failures targeting a user account from the same source address within a short time interval. Adversaries will often brute force login attempts across multiple users with a common or known password, in an attempt to gain access to these accounts.

update

10

Potential Successful Linux FTP Brute Force Attack Detected

An FTP (file transfer protocol) brute force attack is a method where an attacker systematically tries different combinations of usernames and passwords to gain unauthorized access to an FTP server, and if successful, the impact can include unauthorized data access, manipulation, or theft, compromising the security and integrity of the server and potentially exposing sensitive information. This rule identifies multiple consecutive authentication failures targeting a specific user account from the same source address and within a short time interval, followed by a successful authentication.

update

7

Potential Successful Linux RDP Brute Force Attack Detected

An RDP (Remote Desktop Protocol) brute force attack involves an attacker repeatedly attempting various username and password combinations to gain unauthorized access to a remote computer via RDP, and if successful, the potential impact can include unauthorized control over the compromised system, data theft, or the ability to launch further attacks within the network, jeopardizing the security and confidentiality of the targeted system and potentially compromising the entire network infrastructure. This rule identifies multiple consecutive authentication failures targeting a specific user account within a short time interval, followed by a successful authentication.

update

7

Potential Successful SSH Brute Force Attack

Identifies multiple SSH login failures followed by a successful one from the same source address. Adversaries can attempt to login into multiple users with a common or known password to gain access to accounts.

update

10

Potential Linux Credential Dumping via Proc Filesystem

Identifies the execution of the mimipenguin exploit script which is linux adaptation of Windows tool mimikatz. Mimipenguin exploit script is used to dump clear text passwords from a currently logged-in user. The tool exploits a known vulnerability CVE-2018-20781. Malicious actors can exploit the cleartext credentials in memory by dumping the process and extracting lines that have a high probability of containing cleartext passwords.

update

7

Potential OpenSSH Backdoor Logging Activity

Identifies a Secure Shell (SSH) client or server process creating or writing to a known SSH backdoor log file. Adversaries may modify SSH related binaries for persistence or credential access via patching sensitive functions to enable unauthorized access or to log SSH credentials for exfiltration.

update

109

Attempt to Disable IPTables or Firewall

Adversaries may attempt to disable the iptables or firewall service in an attempt to affect how a host is allowed to receive or send network traffic.

update

7

Attempt to Disable Syslog Service

Adversaries may attempt to disable the syslog service in an attempt to an attempt to disrupt event logging and evade detection by security controls.

update

109

Base16 or Base32 Encoding/Decoding Activity

Adversaries may encode/decode data in an attempt to evade detection by host- or network-based security controls.

update

110

System Binary Copied and/or Moved to Suspicious Directory

This rule monitors for the copying or moving of a system binary to a suspicious directory. Adversaries may copy/move and rename system binaries to evade detection. Copying a system binary to a different location should not occur often, so if it does, the activity should be investigated.

update

7

File made Immutable by Chattr

Detects a file being made immutable using the chattr binary. Making a file immutable means it cannot be deleted or renamed, no link can be created to this file, most of the file’s metadata can not be modified, and the file can not be opened in write mode. Threat actors will commonly utilize this to prevent tampering or modification of their malicious files or any system files they have modified for purposes of persistence (e.g .ssh, /etc/passwd, etc.).

update

111

Attempt to Clear Kernel Ring Buffer

Monitors for the deletion of the kernel ring buffer events through dmesg. Attackers may clear kernel ring buffer events to evade detection after installing a Linux kernel module (LKM).

update

4

Potential Disabling of AppArmor

This rule monitors for potential attempts to disable AppArmor. AppArmor is a Linux security module that enforces fine-grained access control policies to restrict the actions and resources that specific applications and processes can access. Adversaries may disable security tools to avoid possible detection of their tools and activities.

update

6

Potential Disabling of SELinux

Identifies potential attempts to disable Security-Enhanced Linux (SELinux), which is a Linux kernel security feature to support access control policies. Adversaries may disable security tools to avoid possible detection of their tools and activities.

update

110

ESXI Timestomping using Touch Command

Identifies instances where the touch command is executed on a Linux system with the "-r" flag, which is used to modify the timestamp of a file based on another file’s timestamp. The rule targets specific VM-related paths, such as "/etc/vmware/", "/usr/lib/vmware/", or "/vmfs/*". These paths are associated with VMware virtualization software, and their presence in the touch command arguments may indicate that a threat actor is attempting to tamper with timestamps of VM-related files and configurations on the system.

update

8

File Deletion via Shred

Malware or other files dropped or created on a system by an adversary may leave traces behind as to what was done within a network and how. Adversaries may remove these files over the course of an intrusion to keep their footprint low or remove them at the end as part of the post-intrusion cleanup process.

update

109

File Permission Modification in Writable Directory

Identifies file permission modifications in common writable directories by a non-root user. Adversaries often drop files or payloads into a writable directory and change permissions prior to execution.

update

210

Creation of Hidden Files and Directories via CommandLine

Users can mark specific files as hidden simply by putting a "." as the first character in the file or folder name. Adversaries can use this to their advantage to hide files and folders on the system for persistence and defense evasion. This rule looks for hidden files or folders in common writable directories.

update

110

Creation of Hidden Shared Object File

Identifies the creation of a hidden shared object (.so) file. Users can mark specific files as hidden simply by putting a "." as the first character in the file or folder name. Adversaries can use this to their advantage to hide files and folders on the system for persistence and defense evasion.

update

110

Kernel Module Removal

Kernel modules are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system. This rule identifies attempts to remove a kernel module.

update

109

Executable Masquerading as Kernel Process

Monitors for kernel processes with associated process executable fields that are not empty. Unix kernel processes such as kthreadd and kworker typically do not have process.executable fields associated to them. Attackers may attempt to hide their malicious programs by masquerading as legitimate kernel processes.

update

2

System Log File Deletion

Identifies the deletion of sensitive Linux system logs. This may indicate an attempt to evade detection or destroy forensic evidence on a system.

update

110

Potential Hidden Process via Mount Hidepid

Identifies the execution of mount process with hidepid parameter, which can make processes invisible to other users from the system. Adversaries using Linux kernel version 3.2+ (or RHEL/CentOS v6.5+ above) can hide the process from other users. When hidepid=2 option is executed to mount the /proc filesystem, only the root user can see all processes and the logged-in user can only see their own process. This provides a defense evasion mechanism for the adversaries to hide their process executions from all other commands such as ps, top, pgrep and more. With the Linux kernel hardening hidepid option all the user has to do is remount the /proc filesystem with the option, which can now be monitored and detected.

update

8

Potential Defense Evasion via PRoot

Identifies the execution of the PRoot utility, an open-source tool for user-space implementation of chroot, mount --bind, and binfmt_misc. Adversaries can leverage an open-source tool PRoot to expand the scope of their operations to multiple Linux distributions and simplify their necessary efforts. In a normal threat scenario, the scope of an attack is limited by the varying configurations of each Linux distribution. With PRoot, it provides an attacker with a consistent operational environment across different Linux distributions, such as Ubuntu, Fedora, and Alpine. PRoot also provides emulation capabilities that allow for malware built on other architectures, such as ARM, to be run.The post-exploitation technique called bring your own filesystem (BYOF), can be used by the threat actors to execute malicious payload or elevate privileges or perform network scans or orchestrate another attack on the environment. Although PRoot was originally not developed with malicious intent it can be easily tuned to work for one.

update

7

Suspicious Renaming of ESXI Files

Identifies instances where VMware-related files, such as those with extensions like ".vmdk", ".vmx", ".vmxf", ".vmsd", ".vmsn", ".vswp", ".vmss", ".nvram", and ".vmem", are renamed on a Linux system. The rule monitors for the "rename" event action associated with these file types, which could indicate malicious activity.

update

6

Suspicious Renaming of ESXI index.html File

Identifies instances where the "index.html" file within the "/usr/lib/vmware/*" directory is renamed on a Linux system. The rule monitors for the "rename" event action associated with this specific file and path, which could indicate malicious activity.

update

6

Potentially Suspicious Process Started via tmux or screen

This rule monitors for the execution of suspicious commands via screen and tmux. When launching a command and detaching directly, the commands will be executed in the background via its parent process. Attackers may leverage screen or tmux to execute commands while attempting to evade detection.

update

4

Suspicious Dynamic Linker Discovery via od

Monitors for dynamic linker discovery via the od utility. od (octal dump) is a command-line utility in Unix operating systems used for displaying data in various formats, including octal, hexadecimal, decimal, and ASCII, primarily used for examining and debugging binary files or data streams. Attackers can leverage od to analyze the dynamic linker by identifying injection points and craft exploits based on the observed behaviors and structures within these files.

update

2

ESXI Discovery via Find

Identifies instances where the find command is started on a Linux system with arguments targeting specific VM-related paths, such as "/etc/vmware/", "/usr/lib/vmware/", or "/vmfs/*". These paths are associated with VMware virtualization software, and their presence in the find command arguments may indicate that a threat actor is attempting to search for, analyze, or manipulate VM-related files and configurations on the system.

update

6

ESXI Discovery via Grep

Identifies instances where a process named grep, egrep, or pgrep is started on a Linux system with arguments related to virtual machine (VM) files, such as "vmdk", "vmx", "vmxf", "vmsd", "vmsn", "vswp", "vmss", "nvram", or "vmem". These file extensions are associated with VM-related file formats, and their presence in grep command arguments may indicate that a threat actor is attempting to search for, analyze, or manipulate VM files on the system.

update

6

Enumeration of Kernel Modules

Loadable Kernel Modules (or LKMs) are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system. This identifies attempts to enumerate information about a kernel module.

update

209

Hping Process Activity

Hping ran on a Linux host. Hping is a FOSS command-line packet analyzer and has the ability to construct network packets for a wide variety of network security testing applications, including scanning and firewall auditing.

update

108

Nping Process Activity

Nping ran on a Linux host. Nping is part of the Nmap tool suite and has the ability to construct raw packets for a wide variety of security testing applications, including denial of service testing.

update

108

Potential Network Scan Executed From Host

This threshold rule monitors for the rapid execution of unix utilities that are capable of conducting network scans. Adversaries may leverage built-in tools such as ping, netcat or socat to execute ping sweeps across the network while attempting to evade detection or due to the lack of network mapping tools available on the compromised host.

update

3

Suspicious /proc/maps Discovery

Monitors for /proc//maps file reads. The /proc//maps file in Linux provides a memory map for a specific process, detailing the memory segments, permissions, and what files are mapped to these segments. Attackers may read a process’s memory map to identify memory addresses for code injection or process hijacking.

update

2

Process Capability Enumeration

Identifies recursive process capability enumeration of the entire filesystem through the getcap command. Malicious users may manipulate identified capabilities to gain root privileges.

update

2

Potential Pspy Process Monitoring Detected

This rule leverages auditd to monitor for processes scanning different processes within the /proc directory using the openat syscall. This is a strong indication for the usage of the pspy utility. Attackers may leverage the pspy process monitoring utility to monitor system processes without requiring root permissions, in order to find potential privilege escalation vectors.

update

7

Sudo Command Enumeration Detected

This rule monitors for the usage of the sudo -l command, which is used to list the allowed and forbidden commands for the invoking user. Attackers may execute this command to enumerate commands allowed to be executed with sudo permissions, potentially allowing to escalate privileges to root.

update

5

SUID/SGUID Enumeration Detected

This rule monitors for the usage of the "find" command in conjunction with SUID and SGUID permission arguments. SUID (Set User ID) and SGID (Set Group ID) are special permissions in Linux that allow a program to execute with the privileges of the file owner or group, respectively, rather than the privileges of the user running the program. In case an attacker is able to enumerate and find a binary that is misconfigured, they might be able to leverage this misconfiguration to escalate privileges by exploiting vulnerabilities or built-in features in the privileged program.

update

5

Suspicious which Enumeration

This rule monitors for the usage of the which command with an unusual amount of process arguments. Attackers may leverage the which command to enumerate the system for useful installed utilities that may be used after compromising a system to escalate privileges or move latteraly across the network.

update

5

Unusual User Privilege Enumeration via id

This rule monitors for a sequence of 20 "id" command executions within 1 second by the same parent process. This behavior is unusual, and may be indicative of the execution of an enumeration script such as LinPEAS or LinEnum. These scripts leverage the "id" command to enumerate the privileges of all users present on the system.

update

4

Virtual Machine Fingerprinting

An adversary may attempt to get detailed information about the operating system and hardware. This rule identifies common locations used to discover virtual machine hardware by a non-root user. This technique has been used by the Pupy RAT and other malware.

update

108

Abnormal Process ID or Lock File Created

Identifies the creation of a Process ID (PID), lock or reboot file created in temporary file storage paradigm (tmpfs) directory /var/run. On Linux, the PID files typically hold the process ID to track previous copies running and manage other tasks. Certain Linux malware use the /var/run directory for holding data, executables and other tasks, disguising itself or these files as legitimate PID files.

update

213

Potential curl CVE-2023-38545 Exploitation

Detects potential exploitation of curl CVE-2023-38545 by monitoring for vulnerable command line arguments in conjunction with an unusual command line length. A flaw in curl version ⇐ 8.3 makes curl vulnerable to a heap based buffer overflow during the SOCKS5 proxy handshake. Upgrade to curl version >= 8.4 to patch this vulnerability. This exploit can be executed with and without the use of environment variables. For increased visibility, enable the collection of http_proxy, HTTPS_PROXY and ALL_PROXY environment variables based on the instructions provided in the setup guide of this rule.

update

5

File Creation, Execution and Self-Deletion in Suspicious Directory

This rule monitors for the creation of a file, followed by its execution and self-deletion in a short timespan within a directory often used for malicious purposes by threat actors. This behavior is often used by malware to execute malicious code and delete itself to hide its tracks.

update

4

File Transfer or Listener Established via Netcat

A netcat process is engaging in network activity on a Linux host. Netcat is often used as a persistence mechanism by exporting a reverse shell or by serving a shell on a listening port. Netcat is also sometimes used for data exfiltration.

update

110

Potential Upgrade of Non-interactive Shell

Identifies when a non-interactive terminal (tty) is being upgraded to a fully interactive shell. Attackers may upgrade a simple reverse shell to a fully interactive tty after obtaining initial access to a host, in order to obtain a more stable connection.

update

3

Netcat Listener Established via rlwrap

Monitors for the execution of a netcat listener via rlwrap. rlwrap is a readline wrapper, a small utility that uses the GNU Readline library to allow the editing of keyboard input for any command. This utility can be used in conjunction with netcat to gain a more stable reverse shell.

update

3

Network Connection via Recently Compiled Executable

This rule monitors a sequence involving a program compilation event followed by its execution and a subsequent network connection event. This behavior can indicate the set up of a reverse tcp connection to a command-and-control server. Attackers may spawn reverse shells to establish persistence onto a target system.

update

5

Interactive Terminal Spawned via Perl

Identifies when a terminal (tty) is spawned via Perl. Attackers may upgrade a simple reverse shell to a fully interactive tty after obtaining initial access to a host.

update

108

Potential Linux Hack Tool Launched

Monitors for the execution of different processes that might be used by attackers for malicious intent. An alert from this rule should be investigated further, as hack tools are commonly used by blue teamers and system administrators as well.

update

3

Process Started from Process ID (PID) File

Identifies a new process starting from a process ID (PID), lock or reboot file within the temporary file storage paradigm (tmpfs) directory /var/run directory. On Linux, the PID files typically hold the process ID to track previous copies running and manage other tasks. Certain Linux malware use the /var/run directory for holding data, executables and other tasks, disguising itself or these files as legitimate PID files.

update

109

Binary Executed from Shared Memory Directory

Identifies the execution of a binary by root in Linux shared memory directories: (/dev/shm/, /run/shm/, /var/run/, /var/lock/). This activity is to be considered highly abnormal and should be investigated. Threat actors have placed executables used for persistence on high-uptime servers in these directories as system backdoors.

update

110

Interactive Terminal Spawned via Python

Identifies when a terminal (tty) is spawned via Python. Attackers may upgrade a simple reverse shell to a fully interactive tty after obtaining initial access to a host.

update

110

Potential Code Execution via Postgresql

This rule monitors for suspicious activities that may indicate an attacker attempting to execute arbitrary code within a PostgreSQL environment. Attackers can execute code via PostgreSQL as a result of gaining unauthorized access to a public facing PostgreSQL database or exploiting vulnerabilities, such as remote command execution and SQL injection attacks, which can result in unauthorized access and malicious actions, and facilitate post-exploitation activities for unauthorized access and malicious actions.

update

6

Linux Restricted Shell Breakout via Linux Binary(s)

Identifies the abuse of a Linux binary to break out of a restricted shell or environment by spawning an interactive system shell. The activity of spawning a shell from a binary is not common behavior for a user or system administrator, and may indicate an attempt to evade detection, increase capabilities or enhance the stability of an adversary.

update

112

Potential Reverse Shell via Background Process

Monitors for the execution of background processes with process arguments capable of opening a socket in the /dev/tcp channel. This may indicate the creation of a backdoor reverse connection, and should be investigated further.

update

4

Potential Reverse Shell via Child

This detection rule identifies suspicious network traffic patterns associated with TCP reverse shell activity. This activity consists of a network event that is followed by the creation of a shell process with suspicious command line arguments. An attacker may establish a Linux TCP reverse shell to gain remote access to a target system.

update

2

Potential Reverse Shell via Java

This detection rule identifies the execution of a Linux shell process from a Java JAR application post an incoming network connection. This behavior may indicate reverse shell activity via a Java application.

update

8

Potential Reverse Shell via Suspicious Child Process

This detection rule detects the creation of a shell through a suspicious process chain. Any reverse shells spawned by the specified utilities that are initialized from a single process followed by a network connection attempt will be captured through this rule. Attackers may spawn reverse shells to establish persistence onto a target system.

update

9

Potential Meterpreter Reverse Shell

This detection rule identifies a sample of suspicious Linux system file reads used for system fingerprinting, leveraged by the Metasploit Meterpreter shell to gather information about the target that it is executing its shell on. Detecting this pattern is indicative of a successful meterpreter shell connection.

update

6

Potential Reverse Shell via Suspicious Binary

This detection rule detects the creation of a shell through a chain consisting of the execution of a suspicious binary (located in a commonly abused location or executed manually) followed by a network event and ending with a shell being spawned. Stageless reverse tcp shells display this behaviour. Attackers may spawn reverse shells to establish persistence onto a target system.

update

7

Potential Reverse Shell

This detection rule identifies suspicious network traffic patterns associated with TCP reverse shell activity. This activity consists of a parent-child relationship where a network event is followed by the creation of a shell process. An attacker may establish a Linux TCP reverse shell to gain remote access to a target system.

update

8

Potential Reverse Shell via UDP

This detection rule identifies suspicious network traffic patterns associated with UDP reverse shell activity. This activity consists of a sample of an execve, socket and connect syscall executed by the same process, where the auditd.data.a0-1 indicate a UDP connection, ending with an egress connection event. An attacker may establish a Linux UDP reverse shell to bypass traditional firewall restrictions and gain remote access to a target system covertly.

update

6

Suspicious Content Extracted or Decompressed via Funzip

Identifies when suspicious content is extracted from a file and subsequently decompressed using the funzip utility. Malware may execute the tail utility using the "-c" option to read a sequence of bytes from the end of a file. The output from tail can be piped to funzip in order to decompress malicious code before it is executed. This behavior is consistent with malware families such as Bundlore.

update

5

Suspicious System Commands Executed by Previously Unknown Executable

This rule monitors for the execution of several commonly used system commands executed by a previously unknown executable located in commonly abused directories. An alert from this rule can indicate the presence of potentially malicious activity, such as the execution of unauthorized or suspicious processes attempting to run malicious code. Detecting and investigating such behavior can help identify and mitigate potential security threats, protecting the system and its data from potential compromise.

update

105

Suspicious Mining Process Creation Event

Identifies service creation events of common mining services, possibly indicating the infection of a system with a cryptominer.

update

6

BPF filter applied using TC

Detects when the tc (transmission control) binary is utilized to set a BPF (Berkeley Packet Filter) on a network interface. Tc is used to configure Traffic Control in the Linux kernel. It can shape, schedule, police and drop traffic. A threat actor can utilize tc to set a bpf filter on an interface for the purpose of manipulating the incoming traffic. This technique is not at all common and should indicate abnormal, suspicious or malicious activity.

update

108

Suspicious Data Encryption via OpenSSL Utility

Identifies when the openssl command-line utility is used to encrypt multiple files on a host within a short time window. Adversaries may encrypt data on a single or multiple systems in order to disrupt the availability of their target’s data and may attempt to hold the organization’s data to ransom for the purposes of extortion.

update

6

Suspicious Termination of ESXI Process

Identifies instances where VMware processes, such as "vmware-vmx" or "vmx," are terminated on a Linux system by a "kill" command. The rule monitors for the "end" event type, which signifies the termination of a process. The presence of a "kill" command as the parent process for terminating VMware processes may indicate that a threat actor is attempting to interfere with the virtualized environment on the targeted system.

update

6

Suspicious File Changes Activity Detected

This rule identifies a sequence of 100 file extension rename events within a set of common file paths by the same process in a timespan of 1 second. Ransomware is a type of malware that encrypts a victim’s files or systems and demands payment (usually in cryptocurrency) in exchange for the decryption key. One important indicator of a ransomware attack is the mass encryption of the file system, after which a new file extension is added to the file.

update

8

Potential Linux Ransomware Note Creation Detected

This rule identifies a sequence of a mass file encryption event in conjunction with the creation of a .txt file with a file name containing ransomware keywords executed by the same process in a 1 second timespan. Ransomware is a type of malware that encrypts a victim’s files or systems and demands payment (usually in cryptocurrency) in exchange for the decryption key. One important indicator of a ransomware attack is the mass encryption of the file system, after which a new file extension is added to the file.

update

8

High Number of Process Terminations

This rule identifies a high number (10) of process terminations via pkill from the same host within a short time period.

update

112

Potential SSH-IT SSH Worm Downloaded

Identifies processes that are capable of downloading files with command line arguments containing URLs to SSH-IT’s autonomous SSH worm. This worm intercepts outgoing SSH connections every time a user uses ssh.

update

3

Connection to External Network via Telnet

Telnet provides a command line interface for communication with a remote device or server. This rule identifies Telnet network connections to publicly routable IP addresses.

update

107

Connection to Internal Network via Telnet

Telnet provides a command line interface for communication with a remote device or server. This rule identifies Telnet network connections to non-publicly routable IP addresses.

update

107

Suspicious APT Package Manager Execution

Detects suspicious process events executed by the APT package manager, potentially indicating persistence through an APT backdoor. In Linux, APT (Advanced Package Tool) is a command-line utility used for handling packages on Debian-based systems, providing functions for installing, updating, upgrading, and removing software along with managing package repositories. Attackers can backdoor APT to gain persistence by injecting malicious code into scripts that APT runs, thereby ensuring continued unauthorized access or control each time APT is used for package management.

update

2

Suspicious APT Package Manager Network Connection

Detects suspicious network events executed by the APT package manager, potentially indicating persistence through an APT backdoor. In Linux, APT (Advanced Package Tool) is a command-line utility used for handling packages on Debian-based systems, providing functions for installing, updating, upgrading, and removing software along with managing package repositories. Attackers can backdoor APT to gain persistence by injecting malicious code into scripts that APT runs, thereby ensuring continued unauthorized access or control each time APT is used for package management.

update

2

Chkconfig Service Add

Detects the use of the chkconfig binary to manually add a service for management by chkconfig. Threat actors may utilize this technique to maintain persistence on a system. When a new service is added, chkconfig ensures that the service has either a start or a kill entry in every runlevel and when the system is rebooted the service file added will run providing long-term persistence.

update

111

Modification of OpenSSH Binaries

Adversaries may modify SSH related binaries for persistence or credential access by patching sensitive functions to enable unauthorized access or by logging SSH credentials for exfiltration.

update

109

Cron Job Created or Changed by Previously Unknown Process

Linux cron jobs are scheduled tasks that can be leveraged by malicious actors for persistence, privilege escalation and command execution. By creating or modifying cron job configurations, attackers can execute malicious commands or scripts at predefined intervals, ensuring their continued presence and enabling unauthorized activities.

update

9

Dynamic Linker Copy

Detects the copying of the Linux dynamic loader binary and subsequent file creation for the purpose of creating a backup copy. This technique was seen recently being utilized by Linux malware prior to patching the dynamic loader in order to inject and preload a malicious shared object file. This activity should never occur and if it does then it should be considered highly suspicious or malicious.

update

108

Suspicious File Creation in /etc for Persistence

Detects the manual creation of files in specific etc directories, via user root, used by Linux malware to persist and elevate privileges on compromised systems. File creation in these directories should not be entirely common and could indicate a malicious binary or script installing persistence mechanisms for long term access.

update

113

Potential Persistence Through init.d Detected

Files that are placed in the /etc/init.d/ directory in Unix can be used to start custom applications, services, scripts or commands during start-up. Init.d has been mostly replaced in favor of Systemd. However, the "systemd-sysv-generator" can convert init.d files to service unit files that run at boot. Adversaries may add or alter files located in the /etc/init.d/ directory to execute malicious code upon boot in order to gain persistence on the system.

update

9

Kernel Module Load via insmod

Detects the use of the insmod binary to load a Linux kernel object file. Threat actors can use this binary, given they have root privileges, to load a rootkit on a system providing them with complete control and the ability to hide from security products. Manually loading a kernel module in this manner should not be at all common and can indicate suspcious or malicious behavior.

update

109

Persistence via KDE AutoStart Script or Desktop File Modification

Identifies the creation or modification of a K Desktop Environment (KDE) AutoStart script or desktop file that will execute upon each user logon. Adversaries may abuse this method for persistence.

update

110

Kernel Driver Load by non-root User

Detects the loading of a Linux kernel module by a non-root user through system calls. Threat actors may leverage Linux kernel modules to load a rootkit on a system providing them with complete control and the ability to hide from security products. As other rules monitor for the addition of Linux kernel modules through system utilities or .ko files, this rule covers the gap that evasive rootkits leverage by monitoring for kernel module additions on the lowest level through auditd_manager.

update

3

Suspicious File Creation via Kworker

This rule monitors for a file creation event originating from a kworker parent process. kworker, or kernel worker, processes are part of the kernel’s workqueue mechanism. They are responsible for executing work that has been scheduled to be done in kernel space, which might include tasks like handling interrupts, background activities, and other kernel-related tasks. Attackers may attempt to evade detection by masquerading as a kernel worker process.

update

3

Potential Linux Backdoor User Account Creation

Identifies the attempt to create a new backdoor user by setting the user’s UID to 0. Attackers may alter a user’s UID to 0 to establish persistence on a system.

update

6

Linux Group Creation

Identifies attempts to create a new group. Attackers may create new groups to establish persistence on a system.

update

4

Potential Remote Code Execution via Web Server

Identifies suspicious commands executed via a web server, which may suggest a vulnerability and remote shell access. Attackers may exploit a vulnerability in a web application to execute commands via a web server, or place a backdoor file that can be abused to gain code execution as a mechanism for persistence.

update

7

Linux User Account Creation

Identifies attempts to create new users. Attackers may add new users to establish persistence on a system.

update

4

Linux User Added to Privileged Group

Identifies attempts to add a user to a privileged group. Attackers may add users to a privileged group in order to establish persistence on a system.

update

6

Potential Persistence Through MOTD File Creation Detected

Message of the day (MOTD) is the message that is presented to the user when a user connects to a Linux server via SSH or a serial connection. Linux systems contain several default MOTD files located in the "/etc/update-motd.d/" and "/usr/lib/update-notifier/" directories. These scripts run as the root user every time a user connects over SSH or a serial connection. Adversaries may create malicious MOTD files that grant them persistence onto the target every time a user connects to the system by executing a backdoor script or command. This rule detects the creation of potentially malicious files within the default MOTD file directories.

update

9

Suspicious Process Spawned from MOTD Detected

Message of the day (MOTD) is the message that is presented to the user when a user connects to a Linux server via SSH or a serial connection. Linux systems contain several default MOTD files located in the "/etc/update-motd.d/" and "/usr/lib/update-notifier/" directories. These scripts run as the root user every time a user connects over SSH or a serial connection. Adversaries may create malicious MOTD files that grant them persistence onto the target every time a user connects to the system by executing a backdoor script or command. This rule detects the execution of potentially malicious processes through the MOTD utility.

update

8

Potential Persistence Through Run Control Detected

This rule monitors the creation/alteration of the rc.local file by a previously unknown process executable through the use of the new terms rule type. The /etc/rc.local file is used to start custom applications, services, scripts or commands during start-up. The rc.local file has mostly been replaced by Systemd. However, through the "systemd-rc-local-generator", rc.local files can be converted to services that run at boot. Adversaries may alter rc.local to execute malicious code at start-up, and gain persistence onto the system.

update

110

Setcap setuid/setgid Capability Set

This rule monitors for the addition of the cap_setuid+ep or cap_setgid+ep capabilities via setcap. Setuid (Set User ID) and setgid (Set Group ID) are Unix-like OS features that enable processes to run with elevated privileges, based on the file owner or group. Threat actors can exploit these attributes to achieve persistence by creating malicious binaries, allowing them to maintain control over a compromised system with elevated permissions.

update

5

Shared Object Created or Changed by Previously Unknown Process

This rule monitors the creation of shared object files by previously unknown processes. The creation of a shared object file involves compiling code into a dynamically linked library that can be loaded by other programs at runtime. While this process is typically used for legitimate purposes, malicious actors can leverage shared object files to execute unauthorized code, inject malicious functionality into legitimate processes, or bypass security controls. This allows malware to persist on the system, evade detection, and potentially compromise the integrity and confidentiality of the affected system and its data.

update

7

Suspicious Network Connection via systemd

Detects suspicious network events executed by systemd, potentially indicating persistence through a systemd backdoor. Systemd is a system and service manager for Linux operating systems, used to initialize and manage system processes. Attackers can backdoor systemd for persistence by creating or modifying systemd unit files to execute malicious scripts or commands, or by replacing legitimate systemd binaries with compromised ones, ensuring that their malicious code is automatically executed at system startup or during certain system events.

update

2

New Systemd Timer Created

Detects the creation of a systemd timer within any of the default systemd timer directories. Systemd timers can be used by an attacker to gain persistence, by scheduling the execution of a command or script. Similarly to cron/at, systemd timers can be set up to execute on boot time, or on a specific point in time, which allows attackers to regain access in case the connection to the infected asset was lost.

update

9

New Systemd Service Created by Previously Unknown Process

Systemd service files are configuration files in Linux systems used to define and manage system services. Malicious actors can leverage systemd service files to achieve persistence by creating or modifying service files to execute malicious commands or payloads during system startup. This allows them to maintain unauthorized access, execute additional malicious activities, or evade detection.

update

9

Tainted Kernel Module Load

This rule monitors the syslog log file for messages related to instances of a tainted kernel module load. Rootkits often leverage kernel modules as their main defense evasion technique. Detecting tainted kernel module loads is crucial for ensuring system security and integrity, as malicious or unauthorized modules can compromise the kernel and lead to system vulnerabilities or unauthorized access.

update

4

Potential Unauthorized Access via Wildcard Injection Detected

This rule monitors for the execution of the "chown" and "chmod" commands with command line flags that could indicate a wildcard injection attack. Linux wildcard injection is a type of security vulnerability where attackers manipulate commands or input containing wildcards (e.g., *, ?, []) to execute unintended operations or access sensitive data by tricking the system into interpreting the wildcard characters in unexpected ways.

update

5

Potential Privilege Escalation via Container Misconfiguration

This rule monitors for the execution of processes that interact with Linux containers through an interactive shell without root permissions. Utilities such as runc and ctr are universal command-line utilities leveraged to interact with containers via root permissions. On systems where the access to these utilities are misconfigured, attackers might be able to create and run a container that mounts the root folder or spawn a privileged container vulnerable to a container escape attack, which might allow them to escalate privileges and gain further access onto the host file system.

update

5

Potential Privilege Escalation via Linux DAC permissions

Identifies potential privilege escalation exploitation of DAC (Discretionary access control) file permissions. The rule identifies exploitation of DAC checks on sensitive file paths via suspicious processes whose capabilities include CAP_DAC_OVERRIDE (where a process can bypass all read write and execution checks) or CAP_DAC_READ_SEARCH (where a process can read any file or perform any executable permission on the directories).

update

2

Potential Chroot Container Escape via Mount

Monitors for the execution of a file system mount followed by a chroot execution. Given enough permissions, a user within a container is capable of mounting the root file system of the host, and leveraging chroot to escape its containarized environment. This behavior pattern is very uncommon and should be investigated.

update

2

Potential Privilege Escalation via Enlightenment

Identifies an attempt to exploit a local privilege escalation CVE-2022-37706 via a flaw in Linux window manager package Enlightenment. enlightenment_sys in Enlightenment before 0.25.4 allows local users to gain privileges because it is setuid root, and the system library function mishandles pathnames that begin with a /dev/.. substring.

update

2

Privilege Escalation via GDB CAP_SYS_PTRACE

Identifies instances where GDB (granted the CAP_SYS_PTRACE capability) is executed, after which the user’s access is elevated to UID/GID 0 (root). In Linux, the CAP_SYS_PTRACE capability grants a process the ability to use the ptrace system call, which is typically used for debugging and allows the process to trace and control other processes. Attackers may leverage this capability to hook and inject into a process that is running with root permissions in order to escalate their privileges to root.

update

2

Root Network Connection via GDB CAP_SYS_PTRACE

Identifies instances where GDB (granted the CAP_SYS_PTRACE capability) is executed, after which an outbound network connection is initiated by UID/GID 0 (root). In Linux, the CAP_SYS_PTRACE capability grants a process the ability to use the ptrace system call, which is typically used for debugging and allows the process to trace and control other processes. Attackers may leverage this capability to hook and inject into a process that is running with root permissions in order to execute shell code and gain a reverse shell with root privileges.

update

2

Suspicious Kworker UID Elevation

Monitors for the elevation of regular user permissions to root permissions through the kworker process. kworker, or kernel worker, processes are part of the kernel’s workqueue mechanism. They are responsible for executing work that has been scheduled to be done in kernel space, which might include tasks like handling interrupts, background activities, and other kernel-related tasks. Attackers may attempt to evade detection by masquerading as a kernel worker process, and hijack the execution flow by hooking certain functions/syscalls through a rootkit in order to provide easy access to root via a special modified command.

update

2

Modification of Dynamic Linker Preload Shared Object

Identifies modification of the dynamic linker preload shared object (ld.so.preload). Adversaries may execute malicious payloads by hijacking the dynamic linker used to load libraries.

update

209

Suspicious Symbolic Link Created

Identifies the creation of a symbolic link to a suspicious file or location. A symbolic link is a reference to a file or directory that acts as a pointer or shortcut, allowing users to access the target file or directory from a different location in the file system. An attacker can potentially leverage symbolic links for privilege escalation by tricking a privileged process into following the symbolic link to a sensitive file, giving the attacker access to data or capabilities they would not normally have.

update

5

Potential Privilege Escalation via UID INT_MAX Bug Detected

This rule monitors for the execution of the systemd-run command by a user with a UID that is larger than the maximum allowed UID size (INT_MAX). Some older Linux versions were affected by a bug which allows user accounts with a UID greater than INT_MAX to escalate privileges by spawning a shell through systemd-run.

update

5

Kernel Load or Unload via Kexec Detected

This detection rule identifies the usage of kexec, helping to uncover unauthorized kernel replacements and potential compromise of the system’s integrity. Kexec is a Linux feature that enables the loading and execution of a different kernel without going through the typical boot process. Malicious actors can abuse kexec to bypass security measures, escalate privileges, establish persistence or hide their activities by loading a malicious kernel, enabling them to tamper with the system’s trusted state, allowing e.g. a VM Escape.

update

6

Potential Privilege Escalation via CVE-2023-4911

This rule detects potential privilege escalation attempts through Looney Tunables (CVE-2023-4911). Looney Tunables is a buffer overflow vulnerability in GNU C Library’s dynamic loader’s processing of the GLIBC_TUNABLES environment variable.

update

4

Suspicious Network Connection via Sudo Binary

Detects network connections initiated by the "sudo" binary. This behavior is uncommon and may occur in instances where reverse shell shellcode is injected into a process run with elevated permissions via "sudo". Attackers may attempt to inject shellcode into processes running as root, to escalate privileges.

update

2

Potential Privilege Escalation via OverlayFS

Identifies an attempt to exploit a local privilege escalation (CVE-2023-2640 and CVE-2023-32629) via a flaw in Ubuntu’s modifications to OverlayFS. These flaws allow the creation of specialized executables, which, upon execution, grant the ability to escalate privileges to root on the affected machine.

update

5

Potential Privilege Escalation via PKEXEC

Identifies an attempt to exploit a local privilege escalation in polkit pkexec (CVE-2021-4034) via unsecure environment variable injection. Successful exploitation allows an unprivileged user to escalate to the root user.

update

108

Potential Buffer Overflow Attack Detected

Detects potential buffer overflow attacks by querying the "Segfault Detected" pre-built rule signal index, through a threshold rule, with a minimum number of 100 segfault alerts in a short timespan. A large amount of segfaults in a short time interval could indicate application exploitation attempts.

update

2

Potential Shell via Wildcard Injection Detected

This rule monitors for the execution of a set of linux binaries, that are potentially vulnerable to wildcard injection, with suspicious command line flags followed by a shell spawn event. Linux wildcard injection is a type of security vulnerability where attackers manipulate commands or input containing wildcards (e.g., *, ?, []) to execute unintended operations or access sensitive data by tricking the system into interpreting the wildcard characters in unexpected ways.

update

5

Potential Suspicious DebugFS Root Device Access

This rule monitors for the usage of the built-in Linux DebugFS utility to access a disk device without root permissions. Linux users that are part of the "disk" group have sufficient privileges to access all data inside of the machine through DebugFS. Attackers may leverage DebugFS in conjunction with "disk" permissions to read sensitive files owned by root, such as the shadow file, root ssh private keys or other sensitive files that may allow them to further escalate privileges.

update

5

Potential Shadow File Read via Command Line Utilities

Identifies access to the /etc/shadow file via the commandline using standard system utilities. After elevating privileges to root, threat actors may attempt to read or dump this file in order to gain valid credentials. They may utilize these to move laterally undetected and access additional resources.

update

208

Potential Sudo Privilege Escalation via CVE-2019-14287

This rule monitors for the execution of a suspicious sudo command that is leveraged in CVE-2019-14287 to escalate privileges to root. Sudo does not verify the presence of the designated user ID and proceeds to execute using a user ID that can be chosen arbitrarily. By using the sudo privileges, the command "sudo -u#-1" translates to an ID of 0, representing the root user. This exploit may work for sudo versions prior to v1.28.

update

4

Potential Sudo Hijacking Detected

Identifies the creation of a sudo binary located at /usr/bin/sudo. Attackers may hijack the default sudo binary and replace it with a custom binary or script that can read the user’s password in clear text to escalate privileges or enable persistence onto the system every time the sudo binary is executed.

update

105

Potential Sudo Token Manipulation via Process Injection

This rule detects potential sudo token manipulation attacks through process injection by monitoring the use of a debugger (gdb) process followed by a successful uid change event during the execution of the sudo process. A sudo token manipulation attack is performed by injecting into a process that has a valid sudo token, which can then be used by attackers to activate their own sudo token. This attack requires ptrace to be enabled in conjunction with the existence of a living process that has a valid sudo token with the same uid as the current user.

update

5

Potential Privilege Escalation via Python cap_setuid

This detection rule monitors for the execution of a system command with setuid or setgid capabilities via Python, followed by a uid or gid change to the root user. This sequence of events may indicate successful privilege escalation. Setuid (Set User ID) and setgid (Set Group ID) are Unix-like OS features that enable processes to run with elevated privileges, based on the file owner or group. Threat actors can exploit these attributes to escalate privileges to the privileges that are set on the binary that is being executed.

update

3

Privilege Escalation via CAP_CHOWN/CAP_FOWNER Capabilities

Identifies instances where a processes (granted CAP_CHOWN and/or CAP_FOWNER capabilities) is executed, after which the ownership of a suspicious file or binary is changed. In Linux, the CAP_CHOWN capability allows a process to change the owner of a file, while CAP_FOWNER permits it to bypass permission checks on operations that require file ownership (like reading, writing, and executing). Attackers may abuse these capabilities to obtain unauthorized access to files.

update

3

Suspicious Passwd File Event Action

Monitors for the generation of a passwd password entry via openssl, followed by a file write activity on the "/etc/passwd" file. The "/etc/passwd" file in Linux stores user account information, including usernames, user IDs, group IDs, home directories, and default shell paths. Attackers may exploit a misconfiguration in the "/etc/passwd" file permissions or other privileges to add a new entry to the "/etc/passwd" file with root permissions, and leverage this new user account to login as root.

update

3

Privilege Escalation via CAP_SETUID/SETGID Capabilities

Identifies instances where a process (granted CAP_SETUID and/or CAP_SETGID capabilities) is executed, after which the user’s access is elevated to UID/GID 0 (root). In Linux, the CAP_SETUID and CAP_SETGID capabilities allow a process to change its UID and GID, respectively, providing control over user and group identity management. Attackers may leverage a misconfiguration for exploitation in order to escalate their privileges to root.

update

2

Potential Privilege Escalation via Recently Compiled Executable

This rule monitors a sequence involving a program compilation event followed by its execution and a subsequent alteration of UID permissions to root privileges. This behavior can potentially indicate the execution of a kernel or software privilege escalation exploit.

update

4

UID Elevation from Previously Unknown Executable

Monitors for the elevation of regular user permissions to root permissions through a previously unknown executable. Attackers may attempt to evade detection by hijacking the execution flow and hooking certain functions/syscalls through a rootkit in order to provide easy access to root via a special modified command.

update

2

Namespace Manipulation Using Unshare

Identifies suspicious usage of unshare to manipulate system namespaces. Unshare can be utilized to escalate privileges or escape container security boundaries. Threat actors have utilized this binary to allow themselves to escape to the host and access other resources or escalate privileges.

update

9

Potential Privilege Escalation through Writable Docker Socket

This rule monitors for the usage of Docker runtime sockets to escalate privileges on Linux systems. Docker sockets by default are only be writable by the root user and docker group. Attackers that have permissions to write to these sockets may be able to create and run a container that allows them to escalate privileges and gain further access onto the host file system.

update

5

Access of Stored Browser Credentials

Identifies the execution of a process with arguments pointing to known browser files that store passwords and cookies. Adversaries may acquire credentials from web browsers by reading files specific to the target browser.

update

107

Access to Keychain Credentials Directories

Adversaries may collect the keychain storage data from a system to acquire credentials. Keychains are the built-in way for macOS to keep track of users' passwords and credentials for many services and features such as WiFi passwords, websites, secure notes and certificates.

update

107

Dumping Account Hashes via Built-In Commands

Identifies the execution of macOS built-in commands used to dump user account hashes. Adversaries may attempt to dump credentials to obtain account login information in the form of a hash. These hashes can be cracked or leveraged for lateral movement.

update

106

Dumping of Keychain Content via Security Command

Adversaries may dump the content of the keychain storage data from a system to acquire credentials. Keychains are the built-in way for macOS to keep track of users' passwords and credentials for many services and features, including Wi-Fi and website passwords, secure notes, certificates, and Kerberos.

update

107

Kerberos Cached Credentials Dumping

Identifies the use of the Kerberos credential cache (kcc) utility to dump locally cached Kerberos tickets. Adversaries may attempt to dump credential material in the form of tickets that can be leveraged for lateral movement.

update

106

Keychain Password Retrieval via Command Line

Adversaries may collect keychain storage data from a system to in order to acquire credentials. Keychains are the built-in way for macOS to keep track of users' passwords and credentials for many services and features, including Wi-Fi and website passwords, secure notes, certificates, and Kerberos.

update

107

WebProxy Settings Modification

Identifies the use of the built-in networksetup command to configure webproxy settings. This may indicate an attempt to hijack web browser traffic for credential access via traffic sniffing or redirection.

update

106

Potential macOS SSH Brute Force Detected

Identifies a high number (20) of macOS SSH KeyGen process executions from the same host. An adversary may attempt a brute force attack to obtain unauthorized access to user accounts.

update

108

Prompt for Credentials with OSASCRIPT

Identifies the use of osascript to execute scripts via standard input that may prompt a user with a rogue dialog for credentials.

update

107

SystemKey Access via Command Line

Keychains are the built-in way for macOS to keep track of users' passwords and credentials for many services and features, including Wi-Fi and website passwords, secure notes, certificates, and Kerberos. Adversaries may collect the keychain storage data from a system to acquire credentials.

update

106

SoftwareUpdate Preferences Modification

Identifies changes to the SoftwareUpdate preferences using the built-in defaults command. Adversaries may abuse this in an attempt to disable security updates.

update

106

Attempt to Remove File Quarantine Attribute

Identifies a potential Gatekeeper bypass. In macOS, when applications or programs are downloaded from the internet, there is a quarantine flag set on the file. This attribute is read by Apple’s Gatekeeper defense program at execution time. An adversary may disable this attribute to evade defenses.

update

107

Attempt to Disable Gatekeeper

Detects attempts to disable Gatekeeper on macOS. Gatekeeper is a security feature that’s designed to ensure that only trusted software is run. Adversaries may attempt to disable Gatekeeper before executing malicious code.

update

106

Attempt to Install Root Certificate

Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to their command and control servers. Root certificates are used in public key cryptography to identify a root certificate authority (CA). When a root certificate is installed, the system or application will trust certificates in the root’s chain of trust that have been signed by the root certificate.

update

106

Modification of Environment Variable via Launchctl

Identifies modifications to an environment variable using the built-in launchctl command. Adversaries may execute their own malicious payloads by hijacking certain environment variables to load arbitrary libraries or bypass certain restrictions.

update

106

Potential Privacy Control Bypass via TCCDB Modification

Identifies the use of sqlite3 to directly modify the Transparency, Consent, and Control (TCC) SQLite database. This may indicate an attempt to bypass macOS privacy controls, including access to sensitive resources like the system camera, microphone, address book, and calendar.

update

107

Potential Privacy Control Bypass via Localhost Secure Copy

Identifies use of the Secure Copy Protocol (SCP) to copy files locally by abusing the auto addition of the Secure Shell Daemon (sshd) to the authorized application list for Full Disk Access. This may indicate attempts to bypass macOS privacy controls to access sensitive files.

update

107

Modification of Safari Settings via Defaults Command

Identifies changes to the Safari configuration using the built-in defaults command. Adversaries may attempt to enable or disable certain Safari settings, such as enabling JavaScript from Apple Events to ease in the hijacking of the users browser.

update

106

Potential Microsoft Office Sandbox Evasion

Identifies the creation of a suspicious zip file prepended with special characters. Sandboxed Microsoft Office applications on macOS are allowed to write files that start with special characters, which can be combined with an AutoStart location to achieve sandbox evasion.

update

106

TCC Bypass via Mounted APFS Snapshot Access

Identifies the use of the mount_apfs command to mount the entire file system through Apple File System (APFS) snapshots as read-only and with the noowners flag set. This action enables the adversary to access almost any file in the file system, including all user data and files protected by Apple’s privacy framework (TCC).

update

106

Attempt to Unload Elastic Endpoint Security Kernel Extension

Identifies attempts to unload the Elastic Endpoint Security kernel extension via the kextunload command.

update

106

Enumeration of Users or Groups via Built-in Commands

Identifies the execution of macOS built-in commands related to account or group enumeration. Adversaries may use account and group information to orient themselves before deciding how to act.

update

107

Execution via Electron Child Process Node.js Module

Identifies attempts to execute a child process from within the context of an Electron application using the child_process Node.js module. Adversaries may abuse this technique to inherit permissions from parent processes.

update

106

Suspicious Browser Child Process

Identifies the execution of a suspicious browser child process. Adversaries may gain access to a system through a user visiting a website over the normal course of browsing. With this technique, the user’s web browser is typically targeted for exploitation.

update

106

MacOS Installer Package Spawns Network Event

Detects the execution of a MacOS installer package with an abnormal child process (e.g bash) followed immediately by a network connection via a suspicious process (e.g curl). Threat actors will build and distribute malicious MacOS installer packages, which have a .pkg extension, many times imitating valid software in order to persuade and infect their victims often using the package files (e.g pre/post install scripts etc.) to download additional tools or malicious software. If this rule fires it should indicate the installation of a malicious or suspicious package.

update

106

Suspicious Automator Workflows Execution

Identifies the execution of the Automator Workflows process followed by a network connection from it’s XPC service. Adversaries may drop a custom workflow template that hosts malicious JavaScript for Automation (JXA) code as an alternative to using osascript.

update

106

Apple Script Execution followed by Network Connection

Detects execution via the Apple script interpreter (osascript) followed by a network connection from the same process within a short time period. Adversaries may use malicious scripts for execution and command and control.

update

106

Shell Execution via Apple Scripting

Identifies the execution of the shell process (sh) via scripting (JXA or AppleScript). Adversaries may use the doShellScript functionality in JXA or do shell script in AppleScript to execute system commands.

update

106

Suspicious macOS MS Office Child Process

Identifies suspicious child processes of frequently targeted Microsoft Office applications (Word, PowerPoint, and Excel). These child processes are often launched during exploitation of Office applications or by documents with malicious macros.

update

106

Potential Kerberos Attack via Bifrost

Identifies use of Bifrost, a known macOS Kerberos pentesting tool, which can be used to dump cached Kerberos tickets or attempt unauthorized authentication techniques such as pass-the-ticket/hash and kerberoasting.

update

106

Attempt to Mount SMB Share via Command Line

Identifies the execution of macOS built-in commands to mount a Server Message Block (SMB) network share. Adversaries may use valid accounts to interact with a remote network share using SMB.

update

107

Remote SSH Login Enabled via systemsetup Command

Detects use of the systemsetup command to enable remote SSH Login.

update

106

Virtual Private Network Connection Attempt

Identifies the execution of macOS built-in commands to connect to an existing Virtual Private Network (VPN). Adversaries may use VPN connections to laterally move and control remote systems on a network.

update

107

Potential Hidden Local User Account Creation

Identifies attempts to create a local account that will be hidden from the macOS logon window. This may indicate an attempt to evade user attention while maintaining persistence using a separate local account.

update

106

Launch Agent Creation or Modification and Immediate Loading

An adversary can establish persistence by installing a new launch agent that executes at login by using launchd or launchctl to load a plist into the appropriate directories.

update

106

Creation of Hidden Login Item via Apple Script

Identifies the execution of osascript to create a hidden login item. This may indicate an attempt to persist a malicious program while concealing its presence.

update

108

LaunchDaemon Creation or Modification and Immediate Loading

Indicates the creation or modification of a launch daemon, which adversaries may use to repeatedly execute malicious payloads as part of persistence.

update

106

Authorization Plugin Modification

Authorization plugins are used to extend the authorization services API and implement mechanisms that are not natively supported by the OS, such as multi-factor authentication with third party software. Adversaries may abuse this feature to persist and/or collect clear text credentials as they traverse the registered plugins during user logon.

update

106

Suspicious CronTab Creation or Modification

Identifies attempts to create or modify a crontab via a process that is not crontab (i.e python, osascript, etc.). This activity should not be highly prevalent and could indicate the use of cron as a persistence mechanism by a threat actor.

update

106

Suspicious Hidden Child Process of Launchd

Identifies the execution of a launchd child process with a hidden file. An adversary can establish persistence by installing a new logon item, launch agent, or daemon that executes upon login.

update

106

Persistence via DirectoryService Plugin Modification

Identifies the creation or modification of a DirectoryService PlugIns (dsplug) file. The DirectoryService daemon launches on each system boot and automatically reloads after crash. It scans and executes bundles that are located in the DirectoryServices PlugIns folder and can be abused by adversaries to maintain persistence.

update

106

Persistence via Docker Shortcut Modification

An adversary can establish persistence by modifying an existing macOS dock property list in order to execute a malicious application instead of the intended one when invoked.

update

106

Emond Rules Creation or Modification

Identifies the creation or modification of the Event Monitor Daemon (emond) rules. Adversaries may abuse this service by writing a rule to execute commands when a defined event occurs, such as system start up or user authentication.

update

107

Suspicious Emond Child Process

Identifies the execution of a suspicious child process of the Event Monitor Daemon (emond). Adversaries may abuse this service by writing a rule to execute commands when a defined event occurs, such as system start up or user authentication.

update

106

Attempt to Enable the Root Account

Identifies attempts to enable the root account using the dsenableroot command. This command may be abused by adversaries for persistence, as the root account is disabled by default.

update

106

Creation of Hidden Launch Agent or Daemon

Identifies the creation of a hidden launch agent or daemon. An adversary may establish persistence by installing a new launch agent or daemon which executes at login.

update

107

Finder Sync Plugin Registered and Enabled

Finder Sync plugins enable users to extend Finder’s functionality by modifying the user interface. Adversaries may abuse this feature by adding a rogue Finder Plugin to repeatedly execute malicious payloads for persistence.

update

106

Persistence via Folder Action Script

Detects modification of a Folder Action script. A Folder Action script is executed when the folder to which it is attached has items added or removed, or when its window is opened, closed, moved, or resized. Adversaries may abuse this feature to establish persistence by utilizing a malicious script.

update

106

Persistence via Login or Logout Hook

Identifies use of the Defaults command to install a login or logoff hook in MacOS. An adversary may abuse this capability to establish persistence in an environment by inserting code to be executed at login or logout.

update

107

Potential Persistence via Login Hook

Identifies the creation or modification of the login window property list (plist). Adversaries may modify plist files to run a program during system boot or user login for persistence.

update

107

Sublime Plugin or Application Script Modification

Adversaries may create or modify the Sublime application plugins or scripts to execute a malicious payload each time the Sublime application is started.

update

107

Potential Persistence via Periodic Tasks

Identifies the creation or modification of the default configuration for periodic tasks. Adversaries may abuse periodic tasks to execute malicious code or maintain persistence.

update

106

Unexpected Child Process of macOS Screensaver Engine

Identifies when a child process is spawned by the screensaver engine process, which is consistent with an attacker’s malicious payload being executed after the screensaver activated on the endpoint. An adversary can maintain persistence on a macOS endpoint by creating a malicious screensaver (.saver) file and configuring the screensaver plist file to execute code each time the screensaver is activated.

update

107

Screensaver Plist File Modified by Unexpected Process

Identifies when a screensaver plist file is modified by an unexpected process. An adversary can maintain persistence on a macOS endpoint by creating a malicious screensaver (.saver) file and configuring the screensaver plist file to execute code each time the screensaver is activated.

update

107

Suspicious Calendar File Modification

Identifies suspicious modifications of the calendar file by an unusual process. Adversaries may create a custom calendar notification procedure to execute a malicious program at a recurring interval to establish persistence.

update

106

Potential Persistence via Atom Init Script Modification

Identifies modifications to the Atom desktop text editor Init File. Adversaries may add malicious JavaScript code to the init.coffee file that will be executed upon the Atom application opening.

update

106

Apple Scripting Execution with Administrator Privileges

Identifies execution of the Apple script interpreter (osascript) without a password prompt and with administrator privileges.

update

107

Execution with Explicit Credentials via Scripting

Identifies execution of the security_authtrampoline process via a scripting interpreter. This occurs when programs use AuthorizationExecute-WithPrivileges from the Security.framework to run another program with root privileges. It should not be run by itself, as this is a sign of execution with explicit logon credentials.

update

106

Suspicious Child Process of Adobe Acrobat Reader Update Service

Detects attempts to exploit privilege escalation vulnerabilities related to the Adobe Acrobat Reader PrivilegedHelperTool responsible for installing updates. For more information, refer to CVE-2020-9615, CVE-2020-9614 and CVE-2020-9613 and verify that the impacted system is patched.

update

106

Potential Admin Group Account Addition

Identifies attempts to add an account to the admin group via the command line. This could be an indication of privilege escalation activity.

update

106

Privilege Escalation via Root Crontab File Modification

Identifies modifications to the root crontab file. Adversaries may overwrite this file to gain code execution with root privileges by exploiting privileged file write or move related vulnerabilities.

update

106

SMTP on Port 26/TCP

This rule detects events that may indicate use of SMTP on TCP port 26. This port is commonly used by several popular mail transfer agents to deconflict with the default SMTP port 25. This port has also been used by a malware family called BadPatch for command and control of Windows systems.

update

104

Exporting Exchange Mailbox via PowerShell

Identifies the use of the Exchange PowerShell cmdlet, New-MailBoxExportRequest, to export the contents of a primary mailbox or archive to a .pst file. Adversaries may target user email to collect sensitive information.

update

110

Exchange Mailbox Export via PowerShell

Identifies the use of the Exchange PowerShell cmdlet, New-MailBoxExportRequest, to export the contents of a primary mailbox or archive to a .pst file. Adversaries may target user email to collect sensitive information.

update

8

PowerShell Suspicious Script with Audio Capture Capabilities

Detects PowerShell scripts that can record audio, a common feature in popular post-exploitation tooling.

update

110

PowerShell Suspicious Script with Clipboard Retrieval Capabilities

Detects PowerShell scripts that can get the contents of the clipboard, which attackers can abuse to retrieve sensitive information like credentials, messages, etc.

update

8

PowerShell Keylogging Script

Detects the use of Win32 API Functions that can be used to capture user keystrokes in PowerShell scripts. Attackers use this technique to capture user input, looking for credentials and/or other valuable data.

update

112

PowerShell Mailbox Collection Script

Detects PowerShell scripts that can be used to collect data from mailboxes. Adversaries may target user email to collect sensitive information.

update

7

PowerShell Suspicious Script with Screenshot Capabilities

Detects PowerShell scripts that can take screenshots, which is a common feature in post-exploitation kits and remote access tools (RATs).

update

108

PowerShell Script with Webcam Video Capture Capabilities

Detects PowerShell scripts that can be used to record webcam video. Attackers can capture this information to extort or spy on victims.

update

4

Encrypting Files with WinRar or 7z

Identifies use of WinRar or 7z to create an encrypted files. Adversaries will often compress and encrypt data in preparation for exfiltration.

update

110

Connection to Commonly Abused Free SSL Certificate Providers

Identifies unusual processes connecting to domains using known free SSL certificates. Adversaries may employ a known encryption algorithm to conceal command and control traffic.

update

106

Potential Command and Control via Internet Explorer

Identifies instances of Internet Explorer (iexplore.exe) being started via the Component Object Model (COM) making unusual network connections. Adversaries could abuse Internet Explorer via COM to avoid suspicious processes making network connections and bypass host-based firewall restrictions.

update

105

Port Forwarding Rule Addition

Identifies the creation of a new port forwarding rule. An adversary may abuse this technique to bypass network segmentation restrictions.

update

109

Potential Remote Desktop Tunneling Detected

Identifies potential use of an SSH utility to establish RDP over a reverse SSH Tunnel. This can be used by attackers to enable routing of network packets that would otherwise not reach their intended destination.

update

109

Remote File Download via Desktopimgdownldr Utility

Identifies the desktopimgdownldr utility being used to download a remote file. An adversary may use desktopimgdownldr to download arbitrary files as an alternative to certutil.

update

111

Remote File Download via MpCmdRun

Identifies the Windows Defender configuration utility (MpCmdRun.exe) being used to download a remote file.

update

111

Remote File Download via Script Interpreter

Identifies built-in Windows script interpreters (cscript.exe or wscript.exe) being used to download an executable file from a remote destination.

update

109

Remote File Copy via TeamViewer

Identifies an executable or script file remotely downloaded via a TeamViewer transfer session.

update

110

Privileged Account Brute Force

Identifies multiple consecutive logon failures targeting an Admin account from the same source address and within a short time interval. Adversaries will often brute force login attempts across multiple users with a common or known password, in an attempt to gain access to accounts.

update

9

Multiple Logon Failure Followed by Logon Success

Identifies multiple logon failures followed by a successful one from the same source address. Adversaries will often brute force login attempts across multiple users with a common or known password, in an attempt to gain access to accounts.

update

10

Multiple Logon Failure from the same Source Address

Identifies multiple consecutive logon failures from the same source address and within a short time interval. Adversaries will often brute force login attempts across multiple users with a common or known password, in an attempt to gain access to accounts.

update

9

Potential Credential Access via Windows Utilities

Identifies the execution of known Windows utilities often abused to dump LSASS memory or the Active Directory database (NTDS.dit) in preparation for credential access.

update

111

NTDS or SAM Database File Copied

Identifies a copy operation of the Active Directory Domain Database (ntds.dit) or Security Account Manager (SAM) files. Those files contain sensitive information including hashed domain and/or local credentials.

update

111

Potential Credential Access via Trusted Developer Utility

An instance of MSBuild, the Microsoft Build Engine, loaded DLLs (dynamically linked libraries) responsible for Windows credential management. This technique is sometimes used for credential dumping.

update

109

FirstTime Seen Account Performing DCSync

This rule identifies when a User Account starts the Active Directory Replication Process for the first time. Attackers can use the DCSync technique to get credential information of individual accounts or the entire domain, thus compromising the entire domain.

update

10

Potential Credential Access via DCSync

This rule identifies when a User Account starts the Active Directory Replication Process. Attackers can use the DCSync technique to get credential information of individual accounts or the entire domain, thus compromising the entire domain.

update

113

Kerberos Pre-authentication Disabled for User

Identifies the modification of an account’s Kerberos pre-authentication options. An adversary with GenericWrite/GenericAll rights over the account can maliciously modify these settings to perform offline password cracking attacks such as AS-REP roasting.

update

110

Creation or Modification of Domain Backup DPAPI private key

Identifies the creation or modification of Domain Backup private keys. Adversaries may extract the Data Protection API (DPAPI) domain backup key from a Domain Controller (DC) to be able to decrypt any domain user master key file.

update

107

Credential Acquisition via Registry Hive Dumping

Identifies attempts to export a registry hive which may contain credentials using the Windows reg.exe tool.

update

109

Full User-Mode Dumps Enabled System-Wide

Identifies the enable of the full user-mode dumps feature system-wide. This feature allows Windows Error Reporting (WER) to collect data after an application crashes. This setting is a requirement for the LSASS Shtinkering attack, which fakes the communication of a crash on LSASS, generating a dump of the process memory, which gives the attacker access to the credentials present on the system without having to bring malware to the system. This setting is not enabled by default, and applications must create their registry subkeys to hold settings that enable them to collect dumps.

update

6

Microsoft IIS Service Account Password Dumped

Identifies the Internet Information Services (IIS) command-line tool, AppCmd, being used to list passwords. An attacker with IIS web server access via a web shell can decrypt and dump the IIS AppPool service account password using AppCmd.

update

109

Microsoft IIS Connection Strings Decryption

Identifies use of aspnet_regiis to decrypt Microsoft IIS connection strings. An attacker with Microsoft IIS web server access via a webshell or alike can decrypt and dump any hardcoded connection strings, such as the MSSQL service account password using aspnet_regiis command.

update

109

Kerberos Traffic from Unusual Process

Identifies network connections to the standard Kerberos port from an unusual process. On Windows, the only process that normally performs Kerberos traffic from a domain joined host is lsass.exe.

update

109

Kirbi File Creation

Identifies the creation of .kirbi files. The creation of this kind of file is an indicator of an attacker running Kerberos ticket dump utilities, such as Mimikatz, and precedes attacks such as Pass-The-Ticket (PTT), which allows the attacker to impersonate users using Kerberos tickets.

update

4

Access to a Sensitive LDAP Attribute

Identify access to sensitive Active Directory object attributes that contains credentials and decryption keys such as unixUserPassword, ms-PKI-AccountCredentials and msPKI-CredentialRoamingTokens.

update

10

Suspicious LSASS Access via MalSecLogon

Identifies suspicious access to LSASS handle from a call trace pointing to seclogon.dll and with a suspicious access rights value. This may indicate an attempt to leak an LSASS handle via abusing the Secondary Logon service in preparation for credential access.

update

208

Suspicious Module Loaded by LSASS

Identifies LSASS loading an unsigned or untrusted DLL. Windows Security Support Provider (SSP) DLLs are loaded into LSSAS process at system start. Once loaded into the LSA, SSP DLLs have access to encrypted and plaintext passwords that are stored in Windows, such as any logged-on user’s Domain password or smart card PINs.

update

7

LSASS Memory Dump Creation

Identifies the creation of a Local Security Authority Subsystem Service (lsass.exe) default memory dump. This may indicate a credential access attempt via trusted system utilities such as Task Manager (taskmgr.exe) and SQL Dumper (sqldumper.exe) or known pentesting tools such as Dumpert and AndrewSpecial.

update

108

LSASS Memory Dump Handle Access

Identifies handle requests for the Local Security Authority Subsystem Service (LSASS) object access with specific access masks that many tools with a capability to dump memory to disk use (0x1fffff, 0x1010, 0x120089). This rule is tool agnostic as it has been validated against a host of various LSASS dump tools such as SharpDump, Procdump, Mimikatz, Comsvcs etc. It detects this behavior at a low level and does not depend on a specific tool or dump file name.

update

110

Mimikatz Memssp Log File Detected

Identifies the password log file from the default Mimikatz memssp module.

update

108

Potential Invoke-Mimikatz PowerShell Script

Mimikatz is a credential dumper capable of obtaining plaintext Windows account logins and passwords, along with many other features that make it useful for testing the security of networks. This rule detects Invoke-Mimikatz PowerShell script and alike.

update

108

Modification of WDigest Security Provider

Identifies attempts to modify the WDigest security provider in the registry to force the user’s password to be stored in clear text in memory. This behavior can be indicative of an adversary attempting to weaken the security configuration of an endpoint. Once the UseLogonCredential value is modified, the adversary may attempt to dump clear text passwords from memory.

update

108

Network Logon Provider Registry Modification

Identifies the modification of the network logon provider registry. Adversaries may register a rogue network logon provider module for persistence and/or credential access via intercepting the authentication credentials in clear text during user logon.

update

108

PowerShell Invoke-NinjaCopy script

Detects PowerShell scripts that contain the default exported functions used on Invoke-NinjaCopy. Attackers can use Invoke-NinjaCopy to read SYSTEM files that are normally locked, such as the NTDS.dit file or registry hives.

update

5

PowerShell Kerberos Ticket Dump

Detects PowerShell scripts that have the capability of dumping Kerberos tickets from LSA, which potentially indicates an attacker’s attempt to acquire credentials for lateral movement.

update

4

PowerShell MiniDump Script

This rule detects PowerShell scripts capable of dumping process memory using WindowsErrorReporting or Dbghelp.dll MiniDumpWriteDump. Attackers can use this tooling to dump LSASS and get access to credentials.

update

108

PowerShell Kerberos Ticket Request

Detects PowerShell scripts that have the capability of requesting kerberos tickets, which is a common step in Kerberoasting toolkits to crack service accounts.

update

111

Potential Credential Access via DuplicateHandle in LSASS

Identifies suspicious access to an LSASS handle via DuplicateHandle from an unknown call trace module. This may indicate an attempt to bypass the NtOpenProcess API to evade detection and dump LSASS memory for credential access.

update

208

Potential Local NTLM Relay via HTTP

Identifies attempt to coerce a local NTLM authentication via HTTP using the Windows Printer Spooler service as a target. An adversary may use this primitive in combination with other techniques to elevate privileges on a compromised system.

update

108

Potential Remote Credential Access via Registry

Identifies remote access to the registry to potentially dump credential data from the Security Account Manager (SAM) registry hive in preparation for credential access and privileges elevation.

update

110

Multiple Vault Web Credentials Read

Windows Credential Manager allows you to create, view, or delete saved credentials for signing into websites, connected applications, and networks. An adversary may abuse this to list or dump credentials stored in the Credential Manager for saved usernames and passwords. This may also be performed in preparation of lateral movement.

update

10

Searching for Saved Credentials via VaultCmd

Windows Credential Manager allows you to create, view, or delete saved credentials for signing into websites, connected applications, and networks. An adversary may abuse this to list or dump credentials stored in the Credential Manager for saved usernames and passwords. This may also be performed in preparation of lateral movement.

update

108

Sensitive Privilege SeEnableDelegationPrivilege assigned to a User

Identifies the assignment of the SeEnableDelegationPrivilege sensitive "user right" to a user. The SeEnableDelegationPrivilege "user right" enables computer and user accounts to be trusted for delegation. Attackers can abuse this right to compromise Active Directory accounts and elevate their privileges.

update

110

Potential Shadow Credentials added to AD Object

Identify the modification of the msDS-KeyCredentialLink attribute in an Active Directory Computer or User Object. Attackers can abuse control over the object and create a key pair, append to raw public key in the attribute, and obtain persistent and stealthy access to the target user or computer object.

update

108

User account exposed to Kerberoasting

Detects when a user account has the servicePrincipalName attribute modified. Attackers can abuse write privileges over a user to configure Service Principle Names (SPNs) so that they can perform Kerberoasting. Administrators can also configure this for legitimate purposes, exposing the account to Kerberoasting.

update

109

Potential Credential Access via Renamed COM+ Services DLL

Identifies suspicious renamed COMSVCS.DLL Image Load, which exports the MiniDump function that can be used to dump a process memory. This may indicate an attempt to dump LSASS memory while bypassing command-line based detection in preparation for credential access.

update

108

Suspicious Lsass Process Access

Identifies access attempts to LSASS handle, this may indicate an attempt to dump credentials from Lsass memory.

update

107

Potential Credential Access via LSASS Memory Dump

Identifies suspicious access to LSASS handle from a call trace pointing to DBGHelp.dll or DBGCore.dll, which both export the MiniDumpWriteDump method that can be used to dump LSASS memory content in preparation for credential access.

update

209

Potential LSASS Memory Dump via PssCaptureSnapShot

Identifies suspicious access to an LSASS handle via PssCaptureSnapShot where two successive process accesses are performed by the same process and target two different instances of LSASS. This may indicate an attempt to evade detection and dump LSASS memory for credential access.

update

208

Suspicious Remote Registry Access via SeBackupPrivilege

Identifies remote access to the registry using an account with Backup Operators group membership. This may indicate an attempt to exfiltrate credentials by dumping the Security Account Manager (SAM) registry hive in preparation for credential access and privileges elevation.

update

110

Symbolic Link to Shadow Copy Created

Identifies the creation of symbolic links to a shadow copy. Symbolic links can be used to access files in the shadow copy, including sensitive files such as ntds.dit, System Boot Key and browser offline credentials.

update

110

Potential LSASS Clone Creation via PssCaptureSnapShot

Identifies the creation of an LSASS process clone via PssCaptureSnapShot where the parent process is the initial LSASS process instance. This may indicate an attempt to evade detection and dump LSASS memory for credential access.

update

106

Suspicious Antimalware Scan Interface DLL

Identifies the creation of the Antimalware Scan Interface (AMSI) DLL in an unusual location. This may indicate an attempt to bypass AMSI by loading a rogue AMSI module instead of the legit one.

update

8

Potential Antimalware Scan Interface Bypass via PowerShell

Identifies the execution of PowerShell script with keywords related to different Antimalware Scan Interface (AMSI) bypasses. An adversary may attempt first to disable AMSI before executing further malicious powershell scripts to evade detection.

update

8

Modification of AmsiEnable Registry Key

Identifies modifications of the AmsiEnable registry key to 0, which disables the Antimalware Scan Interface (AMSI). An adversary can modify this key to disable AMSI protections.

update

109

Clearing Windows Console History

Identifies when a user attempts to clear console history. An adversary may clear the command history of a compromised account to conceal the actions undertaken during an intrusion.

update

110

Clearing Windows Event Logs

Identifies attempts to clear or disable Windows event log stores using Windows wevetutil command. This is often done by attackers in an attempt to evade detection or destroy forensic evidence on a system.

update

111

Code Signing Policy Modification Through Registry

Identifies attempts to disable the code signing policy through the registry. Code signing provides authenticity on a program, and grants the user with the ability to check whether the program has been tampered with. By allowing the execution of unsigned or self-signed code, threat actors can craft and execute malicious code.

update

8

Creation or Modification of Root Certificate

Identifies the creation or modification of a local trusted root certificate in Windows. The install of a malicious root certificate would allow an attacker the ability to masquerade malicious files as valid signed components from any entity (for example, Microsoft). It could also allow an attacker to decrypt SSL traffic.

update

109

Windows CryptoAPI Spoofing Vulnerability (CVE-2020-0601 - CurveBall)

A spoofing vulnerability exists in the way Windows CryptoAPI (Crypt32.dll) validates Elliptic Curve Cryptography (ECC) certificates. An attacker could exploit the vulnerability by using a spoofed code-signing certificate to sign a malicious executable, making it appear the file was from a trusted, legitimate source.

update

104

Windows Defender Disabled via Registry Modification

Identifies modifications to the Windows Defender registry settings to disable the service or set the service to be started manually.

update

110

Windows Defender Exclusions Added via PowerShell

Identifies modifications to the Windows Defender configuration settings using PowerShell to add exclusions at the folder directory or process level.

update

109

PowerShell Script Block Logging Disabled

Identifies attempts to disable PowerShell Script Block Logging via registry modification. Attackers may disable this logging to conceal their activities in the host and evade detection.

update

108

Disable Windows Firewall Rules via Netsh

Identifies use of the netsh.exe to disable or weaken the local firewall. Attackers will use this command line tool to disable the firewall during troubleshooting or to enable network mobility.

update

109

Disabling Windows Defender Security Settings via PowerShell

Identifies use of the Set-MpPreference PowerShell command to disable or weaken certain Windows Defender settings.

update

109

Disable Windows Event and Security Logs Using Built-in Tools

Identifies attempts to disable EventLog via the logman Windows utility, PowerShell, or auditpol. This is often done by attackers in an attempt to evade detection on a system.

update

111

DNS-over-HTTPS Enabled via Registry

Identifies when a user enables DNS-over-HTTPS. This can be used to hide internet activity or the process of exfiltrating data. With this enabled, an organization will lose visibility into data such as query type, response, and originating IP, which are used to determine bad actors.

update

108

Suspicious .NET Code Compilation

Identifies executions of .NET compilers with suspicious parent processes, which can indicate an attacker’s attempt to compile code after delivery in order to bypass security mechanisms.

update

109

Remote Desktop Enabled in Windows Firewall by Netsh

Identifies use of the network shell utility (netsh.exe) to enable inbound Remote Desktop Protocol (RDP) connections in the Windows Firewall.

update

109

Enable Host Network Discovery via Netsh

Identifies use of the netsh.exe program to enable host discovery via the network. Attackers can use this command-line tool to weaken the host firewall settings.

update

108

Control Panel Process with Unusual Arguments

Identifies unusual instances of Control Panel with suspicious keywords or paths in the process command line value. Adversaries may abuse control.exe to proxy execution of malicious code.

update

110

ImageLoad via Windows Update Auto Update Client

Identifies abuse of the Windows Update Auto Update Client (wuauclt.exe) to load an arbitrary DLL. This behavior is used as a defense evasion technique to blend-in malicious activity with legitimate Windows software.

update

111

Microsoft Build Engine Started by an Office Application

An instance of MSBuild, the Microsoft Build Engine, was started by Excel or Word. This is unusual behavior for the Build Engine and could have been caused by an Excel or Word document executing a malicious script payload.

update

109

Microsoft Build Engine Started by a Script Process

An instance of MSBuild, the Microsoft Build Engine, was started by a script or the Windows command interpreter. This behavior is unusual and is sometimes used by malicious payloads.

update

208

Microsoft Build Engine Started by a System Process

An instance of MSBuild, the Microsoft Build Engine, was started by Explorer or the WMI (Windows Management Instrumentation) subsystem. This behavior is unusual and is sometimes used by malicious payloads.

update

109

Microsoft Build Engine Using an Alternate Name

An instance of MSBuild, the Microsoft Build Engine, was started after being renamed. This is uncommon behavior and may indicate an attempt to run unnoticed or undetected.

update

111

Microsoft Build Engine Started an Unusual Process

An instance of MSBuild, the Microsoft Build Engine, started a PowerShell script or the Visual C# Command Line Compiler. This technique is sometimes used to deploy a malicious payload using the Build Engine.

update

210

Potential DLL Side-Loading via Trusted Microsoft Programs

Identifies an instance of a Windows trusted program that is known to be vulnerable to DLL Search Order Hijacking starting after being renamed or from a non-standard path. This is uncommon behavior and may indicate an attempt to evade defenses via side loading a malicious DLL within the memory space of one of those processes.

update

109

Potential DLL Side-Loading via Microsoft Antimalware Service Executable

Identifies a Windows trusted program that is known to be vulnerable to DLL Search Order Hijacking starting after being renamed or from a non-standard path. This is uncommon behavior and may indicate an attempt to evade defenses via side-loading a malicious DLL within the memory space of one of those processes.

update

109

Executable File Creation with Multiple Extensions

Masquerading can allow an adversary to evade defenses and better blend in with the environment. One way it occurs is when the name or location of a file is manipulated as a means of tricking a user into executing what they think is a benign file type but is actually executable code.

update

107

Process Execution from an Unusual Directory

Identifies process execution from suspicious default Windows directories. This is sometimes done by adversaries to hide malware in trusted paths.

update

109

Encoded Executable Stored in the Registry

Identifies registry write modifications to hide an encoded portable executable. This could be indicative of adversary defense evasion by avoiding the storing of malicious content directly on disk.

update

106

IIS HTTP Logging Disabled

Identifies when Internet Information Services (IIS) HTTP Logging is disabled on a server. An attacker with IIS server access via a webshell or other mechanism can disable HTTP Logging as an effective anti-forensics measure.

update

109

Process Injection by the Microsoft Build Engine

An instance of MSBuild, the Microsoft Build Engine, created a thread in another process. This technique is sometimes used to evade detection or elevate privileges.

update

106

InstallUtil Process Making Network Connections

Identifies InstallUtil.exe making outbound network connections. This may indicate adversarial activity as InstallUtil is often leveraged by adversaries to execute code and evade detection.

update

106

Suspicious Endpoint Security Parent Process

A suspicious Endpoint Security parent process was detected. This may indicate a process hollowing or other form of code injection.

update

110

Renamed AutoIt Scripts Interpreter

Identifies a suspicious AutoIt process execution. Malware written as an AutoIt script tends to rename the AutoIt executable to avoid detection.

update

109

Suspicious WerFault Child Process

A suspicious WerFault child process was detected, which may indicate an attempt to run via the SilentProcessExit registry key manipulation. Verify process details such as command line, network connections and file writes.

update

111

Program Files Directory Masquerading

Identifies execution from a directory masquerading as the Windows Program Files directories. These paths are trusted and usually host trusted third party programs. An adversary may leverage masquerading, along with low privileges to bypass detections allowlisting those folders.

update

108

Potential Windows Error Manager Masquerading

Identifies suspicious instances of the Windows Error Reporting process (WerFault.exe or Wermgr.exe) with matching command-line and process executable values performing outgoing network connections. This may be indicative of a masquerading attempt to evade suspicious child process behavior detections.

update

107

Microsoft Windows Defender Tampering

Identifies when one or more features on Microsoft Defender are disabled. Adversaries may disable or tamper with Microsoft Defender features to evade detection and conceal malicious behavior.

update

109

Network Connection via Signed Binary

Binaries signed with trusted digital certificates can execute on Windows systems protected by digital signature validation. Adversaries may use these binaries to live off the land and execute malicious files that could bypass application allowlists and signature validation.

update

107

MS Office Macro Security Registry Modifications

Microsoft Office Products offer options for users and developers to control the security settings for running and using Macros. Adversaries may abuse these security settings to modify the default behavior of the Office Application to trust future macros and/or disable security warnings, which could increase their chances of establishing persistence.

update

107

MsBuild Making Network Connections

Identifies MsBuild.exe making outbound network connections. This may indicate adversarial activity as MsBuild is often leveraged by adversaries to execute code and evade detection.

update

108

Mshta Making Network Connections

Identifies Mshta.exe making outbound network connections. This may indicate adversarial activity, as Mshta is often leveraged by adversaries to execute malicious scripts and evade detection.

update

106

Network Connection via MsXsl

Identifies msxsl.exe making a network connection. This may indicate adversarial activity as msxsl.exe is often leveraged by adversaries to execute malicious scripts and evade detection.

update

105

Unusual Network Activity from a Windows System Binary

Identifies network activity from unexpected system applications. This may indicate adversarial activity as these applications are often leveraged by adversaries to execute code and evade detection.

update

110

Local Account TokenFilter Policy Disabled

Identifies registry modification to the LocalAccountTokenFilterPolicy policy. If this value exists (which doesn’t by default) and is set to 1, then remote connections from all local members of Administrators are granted full high-integrity tokens during negotiation.

update

7

Suspicious .NET Reflection via PowerShell

Detects the use of Reflection.Assembly to load PEs and DLLs in memory in PowerShell scripts. Attackers use this method to load executables and DLLs without writing to the disk, bypassing security solutions.

update

112

PowerShell Suspicious Payload Encoded and Compressed

Identifies the use of .NET functionality for decompression and base64 decoding combined in PowerShell scripts, which malware and security tools heavily use to deobfuscate payloads and load them directly in memory to bypass defenses.

update

111

PowerShell Script with Encryption/Decryption Capabilities

Identifies the use of Cmdlets and methods related to encryption/decryption of files in PowerShell scripts, which malware and offensive security tools can abuse to encrypt data or decrypt payloads to bypass security solutions.

update

6

Potential Process Injection via PowerShell

Detects the use of Windows API functions that are commonly abused by malware and security tools to load malicious code or inject it into remote processes.

update

110

Windows Firewall Disabled via PowerShell

Identifies when the Windows Firewall is disabled using PowerShell cmdlets, which can help attackers evade network constraints, like internet and network lateral communication restrictions.

update

109

Suspicious Microsoft Diagnostics Wizard Execution

Identifies potential abuse of the Microsoft Diagnostics Troubleshooting Wizard (MSDT) to proxy malicious command or binary execution via malicious process arguments.

update

108

Unusual Child Processes of RunDLL32

Identifies child processes of unusual instances of RunDLL32 where the command line parameters were suspicious. Misuse of RunDLL32 could indicate malicious activity.

update

107

Scheduled Tasks AT Command Enabled

Identifies attempts to enable the Windows scheduled tasks AT command via the registry. Attackers may use this method to move laterally or persist locally. The AT command has been deprecated since Windows 8 and Windows Server 2012, but still exists for backwards compatibility.

update

108

Potential Secure File Deletion via SDelete Utility

Detects file name patterns generated by the use of Sysinternals SDelete utility to securely delete a file via multiple file overwrite and rename operations.

update

108

SIP Provider Modification

Identifies modifications to the registered Subject Interface Package (SIP) providers. SIP providers are used by the Windows cryptographic system to validate file signatures on the system. This may be an attempt to bypass signature validation checks or inject code into critical processes.

update

106

SolarWinds Process Disabling Services via Registry

Identifies a SolarWinds binary modifying the start type of a service to be disabled. An adversary may abuse this technique to manipulate relevant security services.

update

108

Suspicious Execution from a Mounted Device

Identifies when a script interpreter or signed binary is launched via a non-standard working directory. An attacker may use this technique to evade defenses.

update

107

Suspicious Managed Code Hosting Process

Identifies a suspicious managed code hosting process which could indicate code injection or other form of suspicious code execution.

update

108

Suspicious Process Access via Direct System Call

Identifies suspicious process access events from an unknown memory region. Endpoint security solutions usually hook userland Windows APIs in order to decide if the code that is being executed is malicious or not. It’s possible to bypass hooked functions by writing malicious functions that call syscalls directly.

update

211

Suspicious Process Creation CallTrace

Identifies when a process is created and immediately accessed from an unknown memory code region and by the same parent process. This may indicate a code injection attempt.

update

208

Suspicious Script Object Execution

Identifies scrobj.dll loaded into unusual Microsoft processes. This usually means a malicious scriptlet is being executed in the target process.

update

107

Renamed Utility Executed with Short Program Name

Identifies the execution of a process with a single character process name, differing from the original file name. This is often done by adversaries while staging, executing temporary utilities, or trying to bypass security detections based on the process name.

update

108

Suspicious WMIC XSL Script Execution

Identifies WMIC allowlist bypass techniques by alerting on suspicious execution of scripts. When WMIC loads scripting libraries it may be indicative of an allowlist bypass.

update

108

Suspicious Zoom Child Process

A suspicious Zoom child process was detected, which may indicate an attempt to run unnoticed. Verify process details such as command line, network connections, file writes and associated file signature details as well.

update

109

Unusual Executable File Creation by a System Critical Process

Identifies an unexpected executable file being created or modified by a Windows system critical process, which may indicate activity related to remote code execution or other forms of exploitation.

update

110

File Creation Time Changed

Identifies modification of a file creation time. Adversaries may modify file time attributes to blend malicious content with existing files. Timestomping is a technique that modifies the timestamps of a file often to mimic files that are in trusted directories.

update

5

Unsigned DLL Side-Loading from a Suspicious Folder

Identifies a Windows trusted program running from locations often abused by adversaries to masquerade as a trusted program and loading a recently dropped DLL. This behavior may indicate an attempt to evade defenses via side-loading a malicious DLL within the memory space of a signed processes.

update

7

Unusual File Creation - Alternate Data Stream

Identifies suspicious creation of Alternate Data Streams on highly targeted files. This is uncommon for legitimate files and sometimes done by adversaries to hide malware.

update

113

Unusual Process Execution Path - Alternate Data Stream

Identifies processes running from an Alternate Data Stream. This is uncommon for legitimate processes and sometimes done by adversaries to hide malware.

update

108

Unusual Network Connection via DllHost

Identifies unusual instances of dllhost.exe making outbound network connections. This may indicate adversarial Command and Control activity.

update

106

Unusual Network Connection via RunDLL32

Identifies unusual instances of rundll32.exe making outbound network connections. This may indicate adversarial Command and Control activity.

update

108

Unusual Process Network Connection

Identifies network activity from unexpected system applications. This may indicate adversarial activity as these applications are often leveraged by adversaries to execute code and evade detection.

update

107

Unusual Child Process from a System Virtual Process

Identifies a suspicious child process of the Windows virtual system process, which could indicate code injection.

update

109

Potential Evasion via Filter Manager

The Filter Manager Control Program (fltMC.exe) binary may be abused by adversaries to unload a filter driver and evade defenses.

update

109

Potential Evasion via Windows Filtering Platform

Identifies multiple Windows Filtering Platform block events and where the process name is related to an endpoint security software. Adversaries may add malicious WFP rules to prevent Endpoint security from sending telemetry.

update

2

Signed Proxy Execution via MS Work Folders

Identifies the use of Windows Work Folders to execute a potentially masqueraded control.exe file in the current working directory. Misuse of Windows Work Folders could indicate malicious activity.

update

108

Host Files System Changes via Windows Subsystem for Linux

Detects files creation and modification on the host system from the the Windows Subsystem for Linux. Adversaries may enable and use WSL for Linux to avoid detection.

update

6

Windows Subsystem for Linux Distribution Installed

Detects changes to the registry that indicates the install of a new Windows Subsystem for Linux distribution by name. Adversaries may enable and use WSL for Linux to avoid detection.

update

6

AdFind Command Activity

This rule detects the Active Directory query tool, AdFind.exe. AdFind has legitimate purposes, but it is frequently leveraged by threat actors to perform post-exploitation Active Directory reconnaissance. The AdFind tool has been observed in Trickbot, Ryuk, Maze, and FIN6 campaigns. For Winlogbeat, this rule requires Sysmon.

update

110

Enumeration of Administrator Accounts

Identifies instances of lower privilege accounts enumerating Administrator accounts or groups using built-in Windows tools.

update

111

Account Discovery Command via SYSTEM Account

Identifies when the SYSTEM account uses an account discovery utility. This could be a sign of discovery activity after an adversary has achieved privilege escalation.

update

110

Group Policy Discovery via Microsoft GPResult Utility

Detects the usage of gpresult.exe to query group policy objects. Attackers may query group policy objects during the reconnaissance phase after compromising a system to gain a better understanding of the active directory environment and possible methods to escalate privileges or move laterally.

update

7

Peripheral Device Discovery

Identifies use of the Windows file system utility (fsutil.exe) to gather information about attached peripheral devices and components connected to a computer system.

update

108

PowerShell Share Enumeration Script

Detects scripts that contain PowerShell functions, structures, or Windows API functions related to windows share enumeration activities. Attackers, mainly ransomware groups, commonly identify and inspect network shares, looking for critical information for encryption and/or exfiltration.

update

9

PowerShell Suspicious Discovery Related Windows API Functions

This rule detects the use of discovery-related Windows API functions in PowerShell Scripts. Attackers can use these functions to perform various situational awareness related activities, like enumerating users, shares, sessions, domain trusts, groups, etc.

update

113

Enumeration of Privileged Local Groups Membership

Identifies instances of an unusual process enumerating built-in Windows privileged local groups membership like Administrators or Remote Desktop users.

update

211

Whoami Process Activity

Identifies suspicious use of whoami.exe which displays user, group, and privileges information for the user who is currently logged on to the local system.

update

110

Command Execution via SolarWinds Process

A suspicious SolarWinds child process (Cmd.exe or Powershell.exe) was detected.

update

110

Suspicious SolarWinds Child Process

A suspicious SolarWinds child process was detected, which may indicate an attempt to execute malicious programs.

update

109

Execution of COM object via Xwizard

Windows Component Object Model (COM) is an inter-process communication (IPC) component of the native Windows application programming interface (API) that enables interaction between software objects or executable code. Xwizard can be used to run a COM object created in registry to evade defensive counter measures.

update

108

Command Prompt Network Connection

Identifies cmd.exe making a network connection. Adversaries could abuse cmd.exe to download or execute malware from a remote URL.

update

107

Svchost spawning Cmd

Identifies a suspicious parent child process relationship with cmd.exe descending from svchost.exe

update

210

Unusual Parent Process for cmd.exe

Identifies a suspicious parent child process relationship with cmd.exe descending from an unusual process.

update

109

Command Shell Activity Started via RunDLL32

Identifies command shell activity started via RunDLL32, which is commonly abused by attackers to host malicious code.

update

109

Enumeration Command Spawned via WMIPrvSE

Identifies native Windows host and network enumeration commands spawned by the Windows Management Instrumentation Provider Service (WMIPrvSE).

update

110

Execution from Unusual Directory - Command Line

Identifies process execution from suspicious default Windows directories. This may be abused by adversaries to hide malware in trusted paths.

update

111

Network Connection via Compiled HTML File

Compiled HTML files (.chm) are commonly distributed as part of the Microsoft HTML Help system. Adversaries may conceal malicious code in a CHM file and deliver it to a victim for execution. CHM content is loaded by the HTML Help executable program (hh.exe).

update

107

Execution of File Written or Modified by Microsoft Office

Identifies an executable created by a Microsoft Office application and subsequently executed. These processes are often launched via scripts inside documents or during exploitation of Microsoft Office applications.

update

109

Execution of File Written or Modified by PDF Reader

Identifies a suspicious file that was written by a PDF reader application and subsequently executed. These processes are often launched via exploitation of PDF applications.

update

107

Potential PowerShell HackTool Script by Function Names

Detects known PowerShell offensive tooling functions names in PowerShell scripts. Attackers commonly use out-of-the-box offensive tools without modifying the code. This rule aim is to take advantage of that.

update

10

Suspicious Portable Executable Encoded in Powershell Script

Detects the presence of a portable executable (PE) in a PowerShell script by looking for its encoded header. Attackers embed PEs into PowerShell scripts to inject them into memory, avoiding defences by not writing to disk.

update

110

PowerShell PSReflect Script

Detects the use of PSReflect in PowerShell scripts. Attackers leverage PSReflect as a library that enables PowerShell to access win32 API functions.

update

110

PsExec Network Connection

Identifies use of the SysInternals tool PsExec.exe making a network connection. This could be an indication of lateral movement.

update

108

Network Connection via Registration Utility

Identifies the native Windows tools regsvr32.exe, regsvr64.exe, RegSvcs.exe, or RegAsm.exe making a network connection. This may be indicative of an attacker bypassing allowlists or running arbitrary scripts via a signed Microsoft binary.

update

107

Outbound Scheduled Task Activity via PowerShell

Identifies the PowerShell process loading the Task Scheduler COM DLL followed by an outbound RPC network connection within a short time period. This may indicate lateral movement or remote discovery via scheduled tasks.

update

106

Execution via local SxS Shared Module

Identifies the creation, change, or deletion of a DLL module within a Windows SxS local folder. Adversaries may abuse shared modules to execute malicious payloads by instructing the Windows module loader to load DLLs from arbitrary local paths.

update

107

Suspicious Cmd Execution via WMI

Identifies suspicious command execution (cmd) via Windows Management Instrumentation (WMI) on a remote host. This could be indicative of adversary lateral movement.

update

110

Suspicious WMI Image Load from MS Office

Identifies a suspicious image load (wmiutils.dll) from Microsoft Office processes. This behavior may indicate adversarial activity where child processes are spawned via Windows Management Instrumentation (WMI). This technique can be used to execute code and evade traditional parent/child processes spawned from Microsoft Office products.

update

107

Suspicious PDF Reader Child Process

Identifies suspicious child processes of PDF reader applications. These child processes are often launched via exploitation of PDF applications or social engineering.

update

109

Suspicious Process Execution via Renamed PsExec Executable

Identifies suspicious psexec activity which is executing from the psexec service that has been renamed, possibly to evade detection.

update

110

Process Activity via Compiled HTML File

Compiled HTML files (.chm) are commonly distributed as part of the Microsoft HTML Help system. Adversaries may conceal malicious code in a CHM file and deliver it to a victim for execution. CHM content is loaded by the HTML Help executable program (hh.exe).

update

109

Conhost Spawned By Suspicious Parent Process

Detects when the Console Window Host (conhost.exe) process is spawned by a suspicious parent process, which could be indicative of code injection.

update

109

Rare SMB Connection to the Internet

This rule detects rare internet network connections via the SMB protocol. SMB is commonly used to leak NTLM credentials via rogue UNC path injection.

update

2

Third-party Backup Files Deleted via Unexpected Process

Identifies the deletion of backup files, saved using third-party software, by a process outside of the backup suite. Adversaries may delete Backup files to ensure that recovery from a ransomware attack is less likely.

update

111

Deleting Backup Catalogs with Wbadmin

Identifies use of the wbadmin.exe to delete the backup catalog. Ransomware and other malware may do this to prevent system recovery.

update

110

Modification of Boot Configuration

Identifies use of bcdedit.exe to delete boot configuration data. This tactic is sometimes used as by malware or an attacker as a destructive technique.

update

108

High Number of Process and/or Service Terminations

This rule identifies a high number (10) of process terminations (stop, delete, or suspend) from the same host within a short time period.

update

108

Volume Shadow Copy Deleted or Resized via VssAdmin

Identifies use of vssadmin.exe for shadow copy deletion or resizing on endpoints. This commonly occurs in tandem with ransomware or other destructive attacks.

update

110

Volume Shadow Copy Deletion via PowerShell

Identifies the use of the Win32_ShadowCopy class and related cmdlets to achieve shadow copy deletion. This commonly occurs in tandem with ransomware or other destructive attacks.

update

110

Volume Shadow Copy Deletion via WMIC

Identifies use of wmic.exe for shadow copy deletion on endpoints. This commonly occurs in tandem with ransomware or other destructive attacks.

update

109

Suspicious HTML File Creation

Identifies the execution of a browser process to open an HTML file with high entropy and size. Adversaries may smuggle data and files past content filters by hiding malicious payloads inside of seemingly benign HTML files.

update

106

Suspicious Execution via Microsoft Office Add-Ins

Identifies execution of common Microsoft Office applications to launch an Office Add-In from a suspicious path or with an unusual parent process. This may indicate an attempt to get initial access via a malicious phishing MS Office Add-In.

update

4

First Time Seen Removable Device

Identifies newly seen removable devices by device friendly name using registry modification events. While this activity is not inherently malicious, analysts can use those events to aid monitoring for data exfiltration over those devices.

update

3

Windows Script Executing PowerShell

Identifies a PowerShell process launched by either cscript.exe or wscript.exe. Observing Windows scripting processes executing a PowerShell script, may be indicative of malicious activity.

update

110

Windows Script Interpreter Executing Process via WMI

Identifies use of the built-in Windows script interpreters (cscript.exe or wscript.exe) being used to execute a process via Windows Management Instrumentation (WMI). This may be indicative of malicious activity.

update

108

Microsoft Exchange Server UM Writing Suspicious Files

Identifies suspicious files being written by the Microsoft Exchange Server Unified Messaging (UM) service. This activity has been observed exploiting CVE-2021-26858.

update

107

Microsoft Exchange Server UM Spawning Suspicious Processes

Identifies suspicious processes being spawned by the Microsoft Exchange Server Unified Messaging (UM) service. This activity has been observed exploiting CVE-2021-26857.

update

108

Microsoft Exchange Worker Spawning Suspicious Processes

Identifies suspicious processes being spawned by the Microsoft Exchange Server worker process (w3wp). This activity may indicate exploitation activity or access to an existing web shell backdoor.

update

108

Suspicious MS Office Child Process

Identifies suspicious child processes of frequently targeted Microsoft Office applications (Word, PowerPoint, Excel). These child processes are often launched during exploitation of Office applications or from documents with malicious macros.

update

111

Suspicious MS Outlook Child Process

Identifies suspicious child processes of Microsoft Outlook. These child processes are often associated with spear phishing activity.

update

110

Suspicious Explorer Child Process

Identifies a suspicious Windows explorer child process. Explorer.exe can be abused to launch malicious scripts or executables from a trusted parent process.

update

108

Service Command Lateral Movement

Identifies use of sc.exe to create, modify, or start services on remote hosts. This could be indicative of adversary lateral movement but will be noisy if commonly done by admins.

update

106

Incoming DCOM Lateral Movement via MSHTA

Identifies the use of Distributed Component Object Model (DCOM) to execute commands from a remote host, which are launched via the HTA Application COM Object. This behavior may indicate an attacker abusing a DCOM application to move laterally while attempting to evade detection.

update

106

Incoming DCOM Lateral Movement with MMC

Identifies the use of Distributed Component Object Model (DCOM) to run commands from a remote host, which are launched via the MMC20 Application COM Object. This behavior may indicate an attacker abusing a DCOM application to move laterally.

update

107

Incoming DCOM Lateral Movement with ShellBrowserWindow or ShellWindows

Identifies use of Distributed Component Object Model (DCOM) to run commands from a remote host, which are launched via the ShellBrowserWindow or ShellWindows Application COM Object. This behavior may indicate an attacker abusing a DCOM application to stealthily move laterally.

update

106

NullSessionPipe Registry Modification

Identifies NullSessionPipe registry modifications that specify which pipes can be accessed anonymously. This could be indicative of adversary lateral movement preparation by making the added pipe available to everyone.

update

107

Potential Remote Desktop Shadowing Activity

Identifies the modification of the Remote Desktop Protocol (RDP) Shadow registry or the execution of processes indicative of an active RDP shadowing session. An adversary may abuse the RDP Shadowing feature to spy on or control other users active RDP sessions.

update

108

Execution via TSClient Mountpoint

Identifies execution from the Remote Desktop Protocol (RDP) shared mountpoint tsclient on the target host. This may indicate a lateral movement attempt.

update

108

Incoming Execution via WinRM Remote Shell

Identifies remote execution via Windows Remote Management (WinRM) remote shell on a target host. This could be an indication of lateral movement.

update

107

WMI Incoming Lateral Movement

Identifies processes executed via Windows Management Instrumentation (WMI) on a remote host. This could be indicative of adversary lateral movement, but could be noisy if administrators use WMI to remotely manage hosts.

update

109

Mounting Hidden or WebDav Remote Shares

Identifies the use of net.exe to mount a WebDav or hidden remote share. This may indicate lateral movement or preparation for data exfiltration.

update

108

Incoming Execution via PowerShell Remoting

Identifies remote execution via Windows PowerShell remoting. Windows PowerShell remoting allows a user to run any Windows PowerShell command on one or more remote computers. This could be an indication of lateral movement.

update

108

RDP Enabled via Registry

Identifies registry write modifications to enable Remote Desktop Protocol (RDP) access. This could be indicative of adversary lateral movement preparation.

update

110

Remote File Copy to a Hidden Share

Identifies a remote file copy attempt to a hidden network share. This may indicate lateral movement or data staging activity.

update

108

Remotely Started Services via RPC

Identifies remote execution of Windows services over remote procedure call (RPC). This could be indicative of lateral movement, but will be noisy if commonly done by administrators."

update

110

Remote Scheduled Task Creation

Identifies remote scheduled task creations on a target host. This could be indicative of adversary lateral movement.

update

107

Suspicious RDP ActiveX Client Loaded

Identifies suspicious Image Loading of the Remote Desktop Services ActiveX Client (mstscax), this may indicate the presence of RDP lateral movement capability.

update

108

Unusual Child Process of dns.exe

Identifies an unexpected process spawning from dns.exe, the process responsible for Windows DNS server services, which may indicate activity related to remote code execution or other forms of exploitation.

update

109

Unusual File Modification by dns.exe

Identifies an unexpected file being modified by dns.exe, the process responsible for Windows DNS Server services, which may indicate activity related to remote code execution or other forms of exploitation.

update

109

Lateral Movement via Startup Folder

Identifies suspicious file creations in the startup folder of a remote system. An adversary could abuse this to move laterally by dropping a malicious script or executable that will be executed after a reboot or user logon.

update

107

Adobe Hijack Persistence

Detects writing executable files that will be automatically launched by Adobe on launch.

update

110

Installation of Custom Shim Databases

Identifies the installation of custom Application Compatibility Shim databases. This Windows functionality has been abused by attackers to stealthily gain persistence and arbitrary code execution in legitimate Windows processes.

update

107

Registry Persistence via AppCert DLL

Detects attempts to maintain persistence by creating registry keys using AppCert DLLs. AppCert DLLs are loaded by every process using the common API functions to create processes.

update

107

Registry Persistence via AppInit DLL

AppInit DLLs are dynamic-link libraries (DLLs) that are loaded into every process that creates a user interface (loads user32.dll) on Microsoft Windows operating systems. The AppInit DLL mechanism is used to load custom code into user-mode processes, allowing for the customization of the user interface and the behavior of Windows-based applications. Attackers who add those DLLs to the registry locations can execute code with elevated privileges, similar to process injection, and provide a solid and constant persistence on the machine.

update

109

Creation of a Hidden Local User Account

Identifies the creation of a hidden local user account by appending the dollar sign to the account name. This is sometimes done by attackers to increase access to a system and avoid appearing in the results of accounts listing using the net users command.

update

109

Image File Execution Options Injection

The Debugger and SilentProcessExit registry keys can allow an adversary to intercept the execution of files, causing a different process to be executed. This functionality can be abused by an adversary to establish persistence.

update

106

Suspicious Startup Shell Folder Modification

Identifies suspicious startup shell folder modifications to change the default Startup directory in order to bypass detections monitoring file creation in the Windows Startup folder.

update

109

Persistence via Scheduled Job Creation

A job can be used to schedule programs or scripts to be executed at a specified date and time. Adversaries may abuse task scheduling functionality to facilitate initial or recurring execution of malicious code.

update

107

Local Scheduled Task Creation

Indicates the creation of a scheduled task. Adversaries can use these to establish persistence, move laterally, and/or escalate privileges.

update

106

Scheduled Task Created by a Windows Script

A scheduled task was created by a Windows script via cscript.exe, wscript.exe or powershell.exe. This can be abused by an adversary to establish persistence.

update

106

Persistence via Microsoft Office AddIns

Detects attempts to establish persistence on an endpoint by abusing Microsoft Office add-ins.

update

107

Persistence via Microsoft Outlook VBA

Detects attempts to establish persistence on an endpoint by installing a rogue Microsoft Outlook VBA Template.

update

106

KRBTGT Delegation Backdoor

Identifies the modification of the msDS-AllowedToDelegateTo attribute to KRBTGT. Attackers can use this technique to maintain persistence to the domain by having the ability to request tickets for the KRBTGT service.

update

107

New ActiveSyncAllowedDeviceID Added via PowerShell

Identifies the use of the Exchange PowerShell cmdlet, Set-CASMailbox, to add a new ActiveSync allowed device. Adversaries may target user email to collect sensitive information.

update

108

Persistence via PowerShell profile

Identifies the creation or modification of a PowerShell profile. PowerShell profile is a script that is executed when PowerShell starts to customize the user environment, which can be abused by attackers to persist in a environment where PowerShell is common.

update

8

Potential Modification of Accessibility Binaries

Windows contains accessibility features that may be launched with a key combination before a user has logged in. An adversary can modify the way these programs are launched to get a command prompt or backdoor without logging in to the system.

update

110

Uncommon Registry Persistence Change

Detects changes to registry persistence keys that are not commonly used or modified by legitimate programs. This could be an indication of an adversary’s attempt to persist in a stealthy manner.

update

106

Execution of Persistent Suspicious Program

Identifies execution of suspicious persistent programs (scripts, rundll32, etc.) by looking at process lineage and command line usage.

update

106

AdminSDHolder SDProp Exclusion Added

Identifies a modification on the dsHeuristics attribute on the bit that holds the configuration of groups excluded from the SDProp process. The SDProp compares the permissions on protected objects with those defined on the AdminSDHolder object. If the permissions on any of the protected accounts and groups do not match, the permissions on the protected accounts and groups are reset to match those of the domain’s AdminSDHolder object, meaning that groups excluded will remain unchanged. Attackers can abuse this misconfiguration to maintain long-term access to privileged accounts in these groups.

update

110

Unusual Persistence via Services Registry

Identifies processes modifying the services registry key directly, instead of through the expected Windows APIs. This could be an indication of an adversary attempting to stealthily persist through abnormal service creation or modification of an existing service.

update

107

Startup Persistence by a Suspicious Process

Identifies files written to or modified in the startup folder by commonly abused processes. Adversaries may use this technique to maintain persistence.

update

109

Persistent Scripts in the Startup Directory

Identifies script engines creating files in the Startup folder, or the creation of script files in the Startup folder. Adversaries may abuse this technique to maintain persistence in an environment.

update

110

Component Object Model Hijacking

Identifies Component Object Model (COM) hijacking via registry modification. Adversaries may establish persistence by executing malicious content triggered by hijacked references to COM objects.

update

111

Suspicious Image Load (taskschd.dll) from MS Office

Identifies a suspicious image load (taskschd.dll) from Microsoft Office processes. This behavior may indicate adversarial activity where a scheduled task is configured via Windows Component Object Model (COM). This technique can be used to configure persistence and evade monitoring by avoiding the usage of the traditional Windows binary (schtasks.exe) used to manage scheduled tasks.

update

108

Suspicious Execution via Scheduled Task

Identifies execution of a suspicious program via scheduled tasks by looking at process lineage and command line usage.

update

107

Suspicious ImagePath Service Creation

Identifies the creation of a suspicious ImagePath value. This could be an indication of an adversary attempting to stealthily persist or escalate privileges through abnormal service creation.

update

106

Suspicious WMI Event Subscription Created

Detects the creation of a WMI Event Subscription. Attackers can abuse this mechanism for persistence or to elevate to SYSTEM privileges.

update

106

Potential Persistence via Time Provider Modification

Identifies modification of the Time Provider. Adversaries may establish persistence by registering and enabling a malicious DLL as a time provider. Windows uses the time provider architecture to obtain accurate time stamps from other network devices or clients in the network. Time providers are implemented in the form of a DLL file which resides in the System32 folder. The service W32Time initiates during the startup of Windows and loads w32time.dll.

update

108

User Added to Privileged Group

Identifies a user being added to a privileged group in Active Directory. Privileged accounts and groups in Active Directory are those to which powerful rights, privileges, and permissions are granted that allow them to perform nearly any action in Active Directory and on domain-joined systems.

update

109

User Account Creation

Identifies attempts to create new users. This is sometimes done by attackers to increase access or establish persistence on a system or domain.

update

108

Potential Application Shimming via Sdbinst

The Application Shim was created to allow for backward compatibility of software as the operating system codebase changes over time. This Windows functionality has been abused by attackers to stealthily gain persistence and arbitrary code execution in legitimate Windows processes.

update

109

Persistence via BITS Job Notify Cmdline

An adversary can use the Background Intelligent Transfer Service (BITS) SetNotifyCmdLine method to execute a program that runs after a job finishes transferring data or after a job enters a specified state in order to persist on a system.

update

106

Persistence via Hidden Run Key Detected

Identifies a persistence mechanism that utilizes the NtSetValueKey native API to create a hidden (null terminated) registry key. An adversary may use this method to hide from system utilities such as the Registry Editor (regedit).

update

107

Installation of Security Support Provider

Identifies registry modifications related to the Windows Security Support Provider (SSP) configuration. Adversaries may abuse this to establish persistence in an environment.

update

107

Persistence via TelemetryController Scheduled Task Hijack

Detects the successful hijack of Microsoft Compatibility Appraiser scheduled task to establish persistence with an integrity level of system.

update

109

Persistence via Update Orchestrator Service Hijack

Identifies potential hijacking of the Microsoft Update Orchestrator Service to establish persistence with an integrity level of SYSTEM.

update

110

Persistence via WMI Event Subscription

An adversary can use Windows Management Instrumentation (WMI) to install event filters, providers, consumers, and bindings that execute code when a defined event occurs. Adversaries may use the capabilities of WMI to subscribe to an event and execute arbitrary code when that event occurs, providing persistence on a system.

update

110

Persistence via WMI Standard Registry Provider

Identifies use of the Windows Management Instrumentation StdRegProv (registry provider) to modify commonly abused registry locations for persistence.

update

107

Execution via MSSQL xp_cmdshell Stored Procedure

Identifies execution via MSSQL xp_cmdshell stored procedure. Malicious users may attempt to elevate their privileges by using xp_cmdshell, which is disabled by default, thus, it’s important to review the context of it’s use.

update

110

Web Shell Detection: Script Process Child of Common Web Processes

Identifies suspicious commands executed via a web server, which may suggest a vulnerability and remote shell access.

update

110

Process Creation via Secondary Logon

Identifies process creation with alternate credentials. Adversaries may create a new process with a different token to escalate privileges and bypass access controls.

update

9

Modification of the msPKIAccountCredentials

Identify the modification of the msPKIAccountCredentials attribute in an Active Directory User Object. Attackers can abuse the credentials roaming feature to overwrite an arbitrary file for privilege escalation. ms-PKI-AccountCredentials contains binary large objects (BLOBs) of encrypted credential objects from the credential manager store, private keys, certificates, and certificate requests.

update

9

Disabling User Account Control via Registry Modification

User Account Control (UAC) can help mitigate the impact of malware on Windows hosts. With UAC, apps and tasks always run in the security context of a non-administrator account, unless an administrator specifically authorizes administrator-level access to the system. This rule identifies registry value changes to bypass User Access Control (UAC) protection.

update

109

Creation or Modification of a new GPO Scheduled Task or Service

Detects the creation or modification of a new Group Policy based scheduled task or service. These methods are used for legitimate system administration, but can also be abused by an attacker with domain admin permissions to execute a malicious payload remotely on all or a subset of the domain joined machines.

update

108

Startup/Logon Script added to Group Policy Object

Detects the modification of Group Policy Objects (GPO) to add a startup/logon script to users or computer objects.

update

109

Group Policy Abuse for Privilege Addition

Detects the first occurrence of a modification to Group Policy Object Attributes to add privileges to user accounts or use them to add users as local admins.

update

109

Scheduled Task Execution at Scale via GPO

Detects the modification of Group Policy Object attributes to execute a scheduled task in the objects controlled by the GPO.

update

110

Potential Privilege Escalation via InstallerFileTakeOver

Identifies a potential exploitation of InstallerTakeOver (CVE-2021-41379) default PoC execution. Successful exploitation allows an unprivileged user to escalate privileges to SYSTEM.

update

110

Interactive Logon by an Unusual Process

Identifies interactive logon attempt with alternate credentials and by an unusual process. Adversaries may create a new token to escalate privileges and bypass access controls.

update

3

Privilege Escalation via Named Pipe Impersonation

Identifies a privilege escalation attempt via named pipe impersonation. An adversary may abuse this technique by utilizing a framework such Metasploit’s meterpreter getsystem command.

update

109

Suspicious DLL Loaded for Persistence or Privilege Escalation

Identifies the loading of a non Microsoft signed DLL that is missing on a default Windows install (phantom DLL) or one that can be loaded from a different location by a native Windows process. This may be abused to persist or elevate privileges via privileged file write vulnerabilities.

update

110

PowerShell Script with Token Impersonation Capabilities

Detects scripts that contain PowerShell functions, structures, or Windows API functions related to token impersonation/theft. Attackers may duplicate then impersonate another user’s token to escalate privileges and bypass access controls.

update

11

Suspicious Print Spooler Point and Print DLL

Detects attempts to exploit a privilege escalation vulnerability (CVE-2020-1030) related to the print spooler service. Exploitation involves chaining multiple primitives to load an arbitrary DLL into the print spooler process running as SYSTEM.

update

105

Suspicious PrintSpooler Service Executable File Creation

Detects attempts to exploit privilege escalation vulnerabilities related to the Print Spooler service. For more information refer to the following CVE’s - CVE-2020-1048, CVE-2020-1337 and CVE-2020-1300 and verify that the impacted system is patched.

update

107

Suspicious Print Spooler File Deletion

Detects deletion of print driver files by an unusual process. This may indicate a clean up attempt post successful privilege escalation via Print Spooler service related vulnerabilities.

update

106

Suspicious Print Spooler SPL File Created

Detects attempts to exploit privilege escalation vulnerabilities related to the Print Spooler service including CVE-2020-1048 and CVE-2020-1337.

update

110

Privilege Escalation via Windir Environment Variable

Identifies a privilege escalation attempt via a rogue Windows directory (Windir) environment variable. This is a known primitive that is often combined with other vulnerabilities to elevate privileges.

update

105

Potential Privileged Escalation via SamAccountName Spoofing

Identifies a suspicious computer account name rename event, which may indicate an attempt to exploit CVE-2021-42278 to elevate privileges from a standard domain user to a user with domain admin privileges. CVE-2021-42278 is a security vulnerability that allows potential attackers to impersonate a domain controller via samAccountName attribute spoofing.

update

108

SeDebugPrivilege Enabled by a Suspicious Process

Identifies the creation of a process running as SYSTEM and impersonating a Windows core binary privileges. Adversaries may create a new process with a different token to escalate privileges and bypass access controls.

update

7

UAC Bypass Attempt with IEditionUpgradeManager Elevated COM Interface

Identifies attempts to bypass User Account Control (UAC) by abusing an elevated COM Interface to launch a rogue Windows ClipUp program. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

update

108

UAC Bypass Attempt via Elevated COM Internet Explorer Add-On Installer

Identifies User Account Control (UAC) bypass attempts by abusing an elevated COM Interface to launch a malicious program. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

update

108

UAC Bypass via ICMLuaUtil Elevated COM Interface

Identifies User Account Control (UAC) bypass attempts via the ICMLuaUtil Elevated COM interface. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

update

108

UAC Bypass via DiskCleanup Scheduled Task Hijack

Identifies User Account Control (UAC) bypass via hijacking DiskCleanup Scheduled Task. Attackers bypass UAC to stealthily execute code with elevated permissions.

update

108

UAC Bypass Attempt via Privileged IFileOperation COM Interface

Identifies attempts to bypass User Account Control (UAC) via DLL side-loading. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

update

108

Bypass UAC via Event Viewer

Identifies User Account Control (UAC) bypass via eventvwr.exe. Attackers bypass UAC to stealthily execute code with elevated permissions.

update

111

UAC Bypass Attempt via Windows Directory Masquerading

Identifies an attempt to bypass User Account Control (UAC) by masquerading as a Microsoft trusted Windows directory. Attackers may bypass UAC to stealthily execute code with elevated permissions.

update

111

UAC Bypass via Windows Firewall Snap-In Hijack

Identifies attempts to bypass User Account Control (UAC) by hijacking the Microsoft Management Console (MMC) Windows Firewall snap-in. Attackers bypass UAC to stealthily execute code with elevated permissions.

update

110

Unusual Parent-Child Relationship

Identifies Windows programs run from unexpected parent processes. This could indicate masquerading or other strange activity on a system.

update

110

Unusual Print Spooler Child Process

Detects unusual Print Spooler service (spoolsv.exe) child processes. This may indicate an attempt to exploit privilege escalation vulnerabilities related to the Printing Service on Windows.

update

107

Unusual Service Host Child Process - Childless Service

Identifies unusual child processes of Service Host (svchost.exe) that traditionally do not spawn any child processes. This may indicate a code injection or an equivalent form of exploitation.

update

109

Privilege Escalation via Rogue Named Pipe Impersonation

Identifies a privilege escalation attempt via rogue named pipe impersonation. An adversary may abuse this technique by masquerading as a known named pipe and manipulating a privileged process to connect to it.

update

106

Windows Service Installed via an Unusual Client

Identifies the creation of a Windows service by an unusual client process. Services may be created with administrator privileges but are executed under SYSTEM privileges, so an adversary may also use a service to escalate privileges from administrator to SYSTEM.

update

108