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
Malicious Metasploit Stager Delivery via mshta Remote HTA (via process_creation)
Suspicious PowerShell Download of Disguised Payload to ProgramData
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Malicious Script Host Spawning PowerShell in Gootloader Chain
Suspicious PsExec Service Launching Encoded PowerShell Payload
Suspicious PowerShell Remote Script Execution via IEX DownloadString
Malicious SharePoint ToolShell Post-Exploitation via Encoded PowerShell (via process_creation)
Suspicious In-Memory PowerShell Execution from Web Server via Automation Assembly (via image_load)
Malicious Qilin Chrome Credential Harvesting Script Execution via IPScanner (via process_creation)
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.