Sigma rule: Suspicious PowerShell Parent Process

Rule

Title

Suspicious PowerShell Parent Process

Status

test

Level

high

Author

Teymur Kheirkhabarov, Harish Segar

Date

2020-03-20

Modified

2023-02-04

File

rules/windows/process_creation/proc_creation_win_powershell_susp_parent_process.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a suspicious or uncommon parent processes of PowerShell

Log source

product

windows

category

process_creation

Detection

selection_parent:
    - ParentImage|contains: 'tomcat'
    - ParentImage|endswith:
          - '\amigo.exe'
          - '\browser.exe'
          - '\chrome.exe'
          - '\firefox.exe'
          - '\httpd.exe'
          - '\iexplore.exe'
          - '\jbosssvc.exe'
          - '\microsoftedge.exe'
          - '\microsoftedgecp.exe'
          - '\MicrosoftEdgeSH.exe'
          - '\mshta.exe'
          - '\nginx.exe'
          - '\outlook.exe'
          - '\php-cgi.exe'
          - '\regsvr32.exe'
          - '\rundll32.exe'
          - '\safari.exe'
          - '\services.exe'
          - '\sqlagent.exe'
          - '\sqlserver.exe'
          - '\sqlservr.exe'
          - '\vivaldi.exe'
          - '\w3wp.exe'
selection_powershell:
    - Image|endswith:
          - '\powershell.exe'
          - '\pwsh.exe'
    - CommandLine|contains:
          - '/c powershell'  # FPs with sub processes that contained "powershell" somewhere in the command line
          - '/c pwsh'
    - Description: 'Windows PowerShell'
    - Product: 'PowerShell Core 6'
    - OriginalFileName:
          - 'PowerShell.EXE'
          - 'pwsh.dll'
condition: all of selection_*

False positives (as the rule lists them)

• Other scripts

Tags

• attack.execution
• attack.t1059.001

MITRE ATT&CK ids this rule names

• T1059.001

Related rules

• 692f0bec-83ba-4d04-af7e-e884a96059b6 (derived)

References

• https://speakerdeck.com/heirhabarov/hunting-for-powershell-abuse?slide=26

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_powershell_susp_parent_process.yml