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Windows Security 4697: cmd.exe Launching Obfuscated PowerShell via Environment Variable Expansion

Alerts on EID 4697 service installation command lines containing obfuscated cmd.exe SET patterns used to execute PowerShell via environment variables.

FreeReviewedSigma · High · v2
Product
windows
Service
security
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 flags Windows Security audit events (EventID 4697) where a service is configured with a ServiceFileName that includes cmd.exe execution of SET with string formatting and environment-variable-based obfuscation consistent with PowerShell invocation. Attackers commonly use environment variable expansion and obfuscated command strings to evade detections and hinder analysis while still executing PowerShell. It relies on Security log telemetry for EventID 4697 and string matching within the ServiceFileName for cmd-related execution indicators.

Reporting behind it

Related detections9 linkedT1027 — drag to rearrange
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Malicious Emmenhtal JavaScript Loader Spawning Encoded PowerShell
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)
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 Security 4697: cmd.exe Launching Obfuscated PowerShell via Environment Variable Expansion
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.