Suspicious Execution from a Mounted Deviceedit
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.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.process-*
- logs-windows.sysmon_operational-*
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: Windows
- Use Case: Threat Detection
- Tactic: Defense Evasion
- Tactic: Execution
- Data Source: Elastic Defend
- Data Source: Sysmon
Version: 108
Rule authors:
- Elastic
Rule license: Elastic License v2
Setupedit
Setup
If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
events will not define event.ingested and default fallback for EQL rules was not added until version 8.2.
Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
event.ingested to @timestamp.
For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
Rule queryedit
process where host.os.type == "windows" and event.type == "start" and process.executable : "C:\\*" and
(process.working_directory : "?:\\" and not process.working_directory: "C:\\") and
process.parent.name : "explorer.exe" and
process.name : ("rundll32.exe", "mshta.exe", "powershell.exe", "pwsh.exe", "cmd.exe", "regsvr32.exe",
"cscript.exe", "wscript.exe")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: System Binary Proxy Execution
- ID: T1218
- Reference URL: https://attack.mitre.org/techniques/T1218/
-
Sub-technique:
- Name: Mshta
- ID: T1218.005
- Reference URL: https://attack.mitre.org/techniques/T1218/005/
-
Sub-technique:
- Name: Regsvr32
- ID: T1218.010
- Reference URL: https://attack.mitre.org/techniques/T1218/010/
-
Sub-technique:
- Name: Rundll32
- ID: T1218.011
- Reference URL: https://attack.mitre.org/techniques/T1218/011/
-
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
-
Technique:
- Name: Command and Scripting Interpreter
- ID: T1059
- Reference URL: https://attack.mitre.org/techniques/T1059/
-
Sub-technique:
- Name: PowerShell
- ID: T1059.001
- Reference URL: https://attack.mitre.org/techniques/T1059/001/
-
Sub-technique:
- Name: Windows Command Shell
- ID: T1059.003
- Reference URL: https://attack.mitre.org/techniques/T1059/003/