huntrule

Windows Process Execution Using Obfuscated CMD to Pipe STDIN into PowerShell

Detects obfuscated cmd executions that launch PowerShell and reference $input/noexit patterns for STDIN-based execution.

FreeReviewedSigma · High · v2
Product
windows
Category
process_creation
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 Windows process executions where an obfuscated cmd command invokes PowerShell while referencing an input stream such as ${input} or -NoExit, consistent with stdin-based launcher behavior. Attackers can use this pattern to hide execution details and dynamically feed commands to PowerShell to reduce detection visibility. The detection relies on process creation telemetry, specifically the CommandLine field matching an obfuscation-tolerant pattern for cmd and PowerShell interaction with input.

Reporting behind it

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Suspicious PS1Bot PowerShell Payload Written to ProgramData (via file_event)
Malicious Non-Interactive Encoded PowerShell Stager (via process_creation)
Suspicious Hidden PowerShell Executing Substring of Dropped File
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
Windows Process Execution Using Obfuscated CMD to Pipe STDIN into PowerShell
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.