Windows MMC Loads Script Engine DLLs (vbscript.dll, jscript.dll, jscript9.dll)

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1059.005Visual Basic
Persistence
Priv Esc
Defense Evasion
- T1218.014MMC
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule triggers when MMC (mmc.exe) loads script engine DLLs such as vbscript.dll, jscript.dll, and jscript9.dll. Attackers can abuse MMC to execute or host script-based payloads within a trusted Windows process, helping with defense evasion or application control bypass attempts. The detection relies on process image load telemetry that records the loaded DLL path for image_load events on Windows.

Reporting behind it

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Windows MMC Loads Script Engine DLLs (vbscript.dll, jscript.dll, jscript9.dll)

Pivot detection · T1059.005 · 9 related

Changelog

v2

v2
Candidate ingested via manual entry.2026-07-31
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.

windows-mmc-loading-script-engine-dlls-vbscript-jscript-a9c73e8b

title: Windows MMC Loads Script Engine DLLs (vbscript.dll, jscript.dll, jscript9.dll)
id: c18055b1-c40c-4009-a29c-cbfbc7cdeed7
status: experimental
description: This rule triggers when MMC (mmc.exe) loads script engine DLLs such as vbscript.dll, jscript.dll, and jscript9.dll. Attackers can abuse MMC to execute or host script-based payloads within a trusted Windows process, helping with defense evasion or application control bypass attempts. The detection relies on process image load telemetry that records the loaded DLL path for image_load events on Windows.
references:
  - https://tria.ge/241015-l98snsyeje/behavioral2
  - https://www.elastic.co/security-labs/grimresource
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/image_load/image_load_win_mmc_loads_script_engine_dll.yml
author: Swachchhanda Shrawan Poudel (Nextron Systems), Huntrule Team
date: 2025-02-05
tags:
  - attack.execution
  - attack.stealth
  - attack.t1059.005
  - attack.t1218.014
logsource:
  category: image_load
  product: windows
detection:
  selection:
    Image|endswith: \mmc.exe
    ImageLoaded|endswith:
      - \vbscript.dll
      - \jscript.dll
      - \jscript9.dll
  condition: selection
falsepositives:
  - Legitimate MMC operations or extensions loading these libraries
level: medium
license: DRL-1.1
related:
  - id: a9c73e8b-3b2d-4c45-8ef2-5f9a9c9998ad
    type: derived

Convert

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