Sigma rule: HackTool - CrackMapExec PowerShell Obfuscation

Rule

Title

HackTool - CrackMapExec PowerShell Obfuscation

Status

test

Level

high

Author

Thomas Patzke

Date

2020-05-22

Modified

2023-02-21

File

rules/windows/process_creation/proc_creation_win_hktl_crackmapexec_powershell_obfuscation.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

The CrachMapExec pentesting framework implements a PowerShell obfuscation with some static strings detected by this rule.

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith:
          - '\powershell.exe'
          - '\pwsh.exe'
    - OriginalFileName:
          - 'PowerShell.EXE'
          - 'pwsh.dll'
selection_cli:
    CommandLine|contains:
        - 'join*split'
        # Line 343ff
        - '( $ShellId[1]+$ShellId[13]+''x'')'
        - '( $PSHome[*]+$PSHOME[*]+'
        - '( $env:Public[13]+$env:Public[5]+''x'')'
        - '( $env:ComSpec[4,*,25]-Join'''')'
        - '[1,3]+''x''-Join'''')'
condition: all of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution
• attack.stealth
• attack.t1059.001
• attack.t1027.005

MITRE ATT&CK ids this rule names

• T1027.005
• T1059.001

References

• https://github.com/byt3bl33d3r/CrackMapExec
• https://github.com/byt3bl33d3r/CrackMapExec/blob/0a49f75347b625e81ee6aa8c33d3970b5515ea9e/cme/helpers/powershell.py#L242

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_hktl_crackmapexec_powershell_obfuscation.yml