huntrule

Windows PowerShell Suspicious Encoded Command-Line Execution

Alerts on PowerShell launched with encoded-command switches and embedded encoded content patterns in the command line.

FreeReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
Florian Roth (Nextron Systems), Markus Neis, Jonhnathan Ribeiro, Daniil Yugoslavskiy, Anton Kutepov, oscd.community (SigmaHQ), DRL 1.1
Published
2018-09-03
Updated
2026-07-30
AnalysisDetection

ATT&CK techniques

Execution

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags Windows PowerShell process creations where the command line indicates encoded execution (e.g., use of the -e/-enc switch) combined with common encoded-content patterns. Attackers often use encoded PowerShell to conceal the true script payload from casual inspection and some detections. Telemetry required is process creation data for Image/PWSh binaries and the full CommandLine text, enabling matching of both encoded switches and characteristic encoded substrings.

Reporting behind it

Related detections9 linkedT1059.001 — drag to rearrange
Suspicious Script Interpreter Spawned by Explorer via ClickFix Run Dialog (via process_creation)
Suspicious PowerShell Download Cradle via ClickFix Fake CAPTCHA (via process_creation)
Suspicious PowerShell EncodedCommand Spawned From Command Shell via Process Creation
Suspicious Script Download via Curl and PowerShell by Dohdoor
Malicious Mass Hyper-V Virtual Machine Shutdown via PowerShell by Kraken Ransomware
Suspicious PowerShell WebClient DownloadFile of Archive Payload (UAT-7237)
Suspicious SharePoint Worker Process Spawning Command Interpreter via ToolShell
Malicious Emmenhtal JavaScript Loader Spawning Encoded PowerShell
Suspicious Python Interpreter Launching Encoded PowerShell via subprocess
Windows PowerShell Suspicious Encoded Command-Line Execution
Pivot detection · T1059.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.