huntrule

Windows PowerShell Process Command Lines With Encoded Command Flags

Alerts on PowerShell (pwsh) command lines using encoded command flags and encoded-looking substrings, excluding gc_worker.exe-related activity.

FreeReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2022-05-24
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 or pwsh process creation events where the command line includes common encoded command options (e.g., -e/-enc) and additional command-line substrings typically seen in encoded payloads. Attackers often use encoded PowerShell to obscure script contents and evade simple command-line inspection. It relies on Windows process creation telemetry, matching Image/OriginalFileName for PowerShell and scanning CommandLine for the specified encoded patterns while excluding activity tied to a specific guest configuration worker process path.

Reporting behind it

Related detections9 linkedT1059.001 — drag to rearrange
Malicious Interlock RAT FileFix Download-Cradle via PowerShell WebClient with PowerShell User-Agent (via ps_script)
Malicious Metasploit Stager Delivery via mshta Remote HTA (via process_creation)
Suspicious PowerShell Download of Disguised Payload to ProgramData
Suspicious PowerShell WebClient Download of Executable Payload
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)
Windows PowerShell Process Command Lines With Encoded Command Flags
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.