VMMap Unsigned Dbghelp.DLL Potential Sideloading — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2023-07-28 / 2023-09-05.

{
  "category": "image_load",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 8c3f93422aa85d6c4ace833090033d59769515f6abef1f90a5c0c2d8fb50cc43

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: VMMap Unsigned Dbghelp.DLL Potential Sideloading
id: 273a8dd8-3742-4302-bcc7-7df5a80fe425
related:
    - id: 98ffaed4-aec2-4e04-9b07-31492fe68b3d
      type: similar
status: test
description: Detects potential DLL sideloading of an unsigned dbghelp.dll by the Sysinternals VMMap.
references:
    - https://techcommunity.microsoft.com/t5/sysinternals-blog/zoomit-v7-1-procdump-2-0-for-linux-process-explorer-v17-05/ba-p/3884766
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-07-28
modified: 2023-09-05
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|contains: 'C:\Debuggers\dbghelp.dll'
        Image|endswith:
            - '\vmmap.exe'
            - '\vmmap64.exe'
    filter_main_signed:
        Signed: 'true'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://techcommunity.microsoft.com/t5/sysinternals-blog/zoomit-v7-1-procdump-2-0-for-linux-process-explorer-v17-05/ba-p/3884766