huntrule

PowerShell Module: Obfuscated STDIN Execution via cmd /c or cmd /r

Alerts when an obfuscated cmd->PowerShell payload uses stdin-style input and noexit/no-execution patterns.

FreeReviewedSigma · High · v2
Product
windows
Category
ps_module
Author
Jonathan Cheong, oscd.community (SigmaHQ), DRL 1.1
Published
2020-10-15
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Execution → Defense Evasion

  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 identifies PowerShell module activity where an obfuscated command line uses cmd with /c or /r and includes PowerShell invocation that reads input from stdin (e.g., ${input} or $input) or related no-exit patterns. Attackers may use this technique to hide payload intent and deliver commands through stdin, complicating analysis and filtering. The detection relies on telemetry capturing the PowerShell module payload or command text and matching it against the specified obfuscation and stdin-based execution pattern.

Reporting behind it

Related detections9 linkedT1027 — drag to rearrange
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Suspicious Python Interpreter Launching Encoded PowerShell via subprocess
Suspicious PS1Bot PowerShell Payload Written to ProgramData (via file_event)
Malicious Non-Interactive Encoded PowerShell Stager (via process_creation)
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PowerShell Encoded or Download-Cradle Command Line (via process_creation)
Obfuscated Encoded PowerShell Payload Deployed - PowerShell (via powershell)
Suspicious PowerShell AES Decryption and Reflective Method Invocation in SolarMarker
PowerShell Module: Obfuscated STDIN Execution via cmd /c or cmd /r
Pivot detection · T1027 · 9 related

Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. v1
    No changelog recorded for this version.2026-07-30

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