Sigma rule: Potential PowerShell Execution Via DLL

Rule

Title

Potential PowerShell Execution Via DLL

Status

test

Level

high

Author

Markus Neis, Nasreddine Bencherchali (Nextron Systems)

Date

2018-08-25

Modified

2024-03-07

File

rules/windows/process_creation/proc_creation_win_susp_powershell_execution_via_dll.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects potential PowerShell execution from a DLL instead of the usual PowerShell process as seen used in PowerShdll.
This detection assumes that PowerShell commands are passed via the CommandLine.

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith:
          - '\InstallUtil.exe'
          - '\RegAsm.exe'
          - '\RegSvcs.exe'
          - '\regsvr32.exe'
          - '\rundll32.exe'
    - OriginalFileName:
          - 'InstallUtil.exe'
          - 'RegAsm.exe'
          - 'RegSvcs.exe'
          - 'REGSVR32.EXE'
          - 'RUNDLL32.EXE'
selection_cli:
    CommandLine|contains:
        - 'Default.GetString'
        - 'DownloadString'
        - 'FromBase64String'
        - 'ICM '
        - 'IEX '
        - 'Invoke-Command'
        - 'Invoke-Expression'
condition: all of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.stealth
• attack.t1218.011

MITRE ATT&CK ids this rule names

• T1218.011

References

• https://github.com/p3nt4/PowerShdll/blob/62cfa172fb4e1f7f4ac00ca942685baeb88ff356/README.md

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_susp_powershell_execution_via_dll.yml