Potential Process Injection via LD_PRELOAD Environment Variableedit
This rule detects the execution of a process where the LD_PRELOAD environment variable is set. LD_PRELOAD can be used to inject a shared library into a binary at or prior to execution. A threat actor may do this in order to load a malicious shared library for the purposes of persistence, privilege escalation, and defense evasion. This activity is not common and will potentially indicate malicious or suspicious behavior.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Linux
- Use Case: Threat Detection
- Tactic: Defense Evasion
- Tactic: Persistence
- Tactic: Privilege Escalation
Version: 1
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guideedit
## Setup By default, the `Elastic Defend` integration does not collect environment variable logging. In order to capture this behavior, this rule requires a specific configuration option set within the advanced settings of the `Elastic Defend` integration. ``` Kibana --> Fleet --> Agent policies --> Agent policy for which the option should be enabled --> Name of the Elastic Defend integration --> Show advanced settings --> linux.advanced.capture_env_vars ``` `linux.advanced.capture_env_vars` should be set to `LD_PRELOAD,LD_LIBRARY_PATH`. After saving the integration change, the Elastic Agents running this policy will be updated and the rule will function properly.
Rule queryedit
process where host.os.type == "linux" and
event.action == "exec" and
process.env_vars : ("LD_PRELOAD=?*", "LD_LIBRARY_PATH=?*")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Hijack Execution Flow
- ID: T1574
- Reference URL: https://attack.mitre.org/techniques/T1574/
-
Sub-technique:
- Name: Dynamic Linker Hijacking
- ID: T1574.006
- Reference URL: https://attack.mitre.org/techniques/T1574/006/
-
Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
-
Technique:
- Name: Hijack Execution Flow
- ID: T1574
- Reference URL: https://attack.mitre.org/techniques/T1574/
-
Sub-technique:
- Name: Dynamic Linker Hijacking
- ID: T1574.006
- Reference URL: https://attack.mitre.org/techniques/T1574/006/
-
Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
-
Technique:
- Name: Hijack Execution Flow
- ID: T1574
- Reference URL: https://attack.mitre.org/techniques/T1574/
-
Sub-technique:
- Name: Dynamic Linker Hijacking
- ID: T1574.006
- Reference URL: https://attack.mitre.org/techniques/T1574/006/