huntrule

Windows rundll32 Executing Inline VBScript via RegRead

Detects rundll32.exe command lines containing inline VBScript execution with RegRead and window.close.

FreeReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2021-03-05
Updated
2026-07-30
AnalysisDetection

ATT&CK techniques

Priv Esc → 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 process creation events where rundll32.exe is launched with a command line containing inline VBScript components for registry reading (RegRead), script execution (Execute), and closing the window (window.close). Attackers commonly use this technique to blend script execution into a trusted Windows binary, enabling stealthy data collection and follow-on actions. Detection relies on process creation telemetry and matching specific command-line substrings indicating rundll32-driven inline VBScript behavior.

Reporting behind it

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Suspicious CRAT Injection Named Pipe ChromeUpdatePipe (via pipe_created)
AsyncRAT Injector libPK.dll Written to Public Folder (via file_event)
FlawedGrace spawning threat injection target
Windows rundll32 Executing Inline VBScript via RegRead
Pivot detection · T1055 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.