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
Malicious FIN7 Powertrash Loader Execution via Obfuscated PowerShell (via process_creation)
Suspicious XOR Obfuscated PowerShell from ClickFix Distribution
Suspicious PowerShell Executing Code from Environment Variable (via process_creation)
Suspicious In-Memory Runspace Execution via PowerShell Script Block
Suspicious Encoded PowerShell Using Base64 Stream Decompression Routines (via process_creation)
Suspicious PowerShell In-Memory Execution with AES Decryption
Suspicious Encoded PowerShell Command Execution
Suspicious PEAKLIGHT Memory-Only PowerShell Downloader Flags (via process_creation)
Obfuscated PowerShell Script: Indirect Cmdlet Execution via ExportedCommands Array Index
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.