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

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
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.