Sigma rule: Potentially Suspicious PowerShell Child Processes

Rule

Title

Potentially Suspicious PowerShell Child Processes

Status

test

Level

medium

Author

Florian Roth (Nextron Systems), Tim Shelton

Date

2022-04-26

Modified

2024-07-16

File

rules-threat-hunting/windows/process_creation/proc_creation_win_powershell_susp_child_processes.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects potentially suspicious child processes spawned by PowerShell.
Use this rule to hunt for potential anomalies initiating from PowerShell scripts and commands.

Log source

product

windows

category

process_creation

Detection

selection:
    ParentImage|endswith:
        - '\powershell_ise.exe'
        - '\powershell.exe'
        - '\pwsh.exe'
    Image|endswith:
        - '\bash.exe'
        - '\bitsadmin.exe'
        - '\certutil.exe'
        - '\cscript.exe'
        - '\forfiles.exe'
        - '\hh.exe'
        - '\mshta.exe'
        - '\regsvr32.exe'
        - '\rundll32.exe'
        - '\schtasks.exe'
        - '\scrcons.exe'
        - '\scriptrunner.exe'
        - '\sh.exe'
        - '\wmic.exe'
        - '\wscript.exe'
filter_optional_amazon:
    ParentCommandLine|contains: '\Program Files\Amazon\WorkspacesConfig\Scripts\'  # AWS Workspaces
    CommandLine|contains: '\Program Files\Amazon\WorkspacesConfig\Scripts\'  # AWS Workspaces
filter_main_certutil_verify_store:
    Image|endswith: '\certutil.exe'
    CommandLine|contains: '-verifystore '
filter_main_wmic:
    Image|endswith: '\wmic.exe'
    CommandLine|contains:
        - 'qfe list'
        - 'diskdrive '
        - 'csproduct '
        - 'computersystem '
        - ' os '
        - ''
condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*

False positives (as the rule lists them)

• False positives are to be expected from PowerShell scripts that might make use of additional binaries such as "mshta", "bitsadmin", etc. Apply additional filters for those scripts.

Tags

• attack.execution
• attack.t1059.001
• detection.threat-hunting

MITRE ATT&CK ids this rule names

• T1059.001

References

• https://twitter.com/ankit_anubhav/status/1518835408502620162

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