huntrule

PowerShell ScriptBlock Logging: Obfuscated RUNDLL Launcher using rundll32.exe and shell32.dll

Identifies PowerShell script content invoking rundll32.exe/shell32.dll via shellexec_rundll and referencing PowerShell.

FreeReviewedSigma · Medium · v2
Product
windows
Category
ps_script
Author
Timur Zinniatullin, oscd.community (SigmaHQ), DRL 1.1
Published
2020-10-18
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 PowerShell script content containing all required strings associated with a RUNDLL launcher technique: rundll32.exe, shell32.dll, shellexec_rundll, and powershell. Attackers may use this pattern to obscure execution paths and launch PowerShell indirectly via Windows library-based execution. The detection relies on Script Block Logging telemetry that provides the full PowerShell ScriptBlockText for string matching.

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
PowerShell ScriptBlock Logging: Obfuscated RUNDLL Launcher using rundll32.exe and shell32.dll
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.