Detection rules › Sigma

VMMap Signed Dbghelp.DLL Potential Sideloading

Status
test
Severity
medium
Log source
category image_load, product windows
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects potential DLL sideloading of a signed dbghelp.dll by the Sysinternals VMMap.

MITRE ATT&CK coverage

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 7: Image loaded

Rule body

title: VMMap Signed Dbghelp.DLL Potential Sideloading
id: 98ffaed4-aec2-4e04-9b07-31492fe68b3d
related:
    - id: 273a8dd8-3742-4302-bcc7-7df5a80fe425
      type: similar
status: test
description: Detects potential DLL sideloading of a signed 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: 2023-09-05
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'
        Signed: 'true'
    condition: selection
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ImageLoaded|contains: 'C:\Debuggers\dbghelp.dll'
    Image|endswith:
        - '\vmmap.exe'
        - '\vmmap64.exe'
    Signed: 'true'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Imageends_with
  • \vmmap.exe corpus 3 (sigma 3)
  • \vmmap64.exe corpus 3 (sigma 3)
field:"Image" kind:ends_with
ImageLoadedmatch
  • C:\Debuggers\dbghelp.dll corpus 2 (sigma 2)
field:"ImageLoaded" kind:match value:"C:\Debuggers\dbghelp.dll"
Signedeq
  • true corpus 2 (sigma 2)
field:"Signed" kind:eq value:"true"