Suspicious Loading of Dbgcore/Dbghelp DLLs from Uncommon Location — Sigma Rule

Rule metadata and linked tags

Author: Swachchhanda Shrawan Poudel (Nextron Systems). Source status: experimental; severity: high. Source dates: 2025-11-27 / 2026-01-09.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 2f0d3c7262faf032ec22817a407baf8c05ee5dabd1fa2840226260a267589700

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: Suspicious Loading of Dbgcore/Dbghelp DLLs from Uncommon Location
id: 416bc4a2-7217-4519-8dc7-c3271817f1d5
related:
    - id: 9f5c1d59-33be-4e60-bcab-85d2f566effd
      type: similar
status: experimental
description: |
    Detects loading of dbgcore.dll or dbghelp.dll from uncommon locations such as user directories.
    These DLLs contain the MiniDumpWriteDump function, which can be abused for credential dumping purposes or in some cases for evading EDR/AV detection by suspending processes.
references:
    - https://blog.axelarator.net/hunting-for-edr-freeze/
    - https://www.zerosalarium.com/2025/09/EDR-Freeze-Puts-EDRs-Antivirus-Into-Coma.html
    - https://www.splunk.com/en_us/blog/security/you-bet-your-lsass-hunting-lsass-access.html
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-11-27
modified: 2026-01-09
tags:
    - attack.credential-access
    - attack.defense-impairment
    - attack.t1003
    - attack.t1685
logsource:
    category: image_load
    product: windows
detection:
    selection_img:
        Image|contains:
            - ':\Perflogs\'
            - ':\Temp\'
            - ':\Users\Public\'
            - '\$Recycle.Bin\'
            - '\Contacts\'
            # - '\Desktop\'
            - '\Documents\'
            # - '\Downloads\'
            - '\Favorites\'
            - '\Favourites\'
            - '\inetpub\wwwroot\'
            - '\Music\'
            - '\Pictures\'
            - '\Start Menu\Programs\Startup\'
            - '\Users\Default\'
            - '\Videos\'
            #  - '\AppData\Local\Temp\' some installers may load from here
    selection_dll:
        ImageLoaded|endswith:
            - '\dbgcore.dll'
            - '\dbghelp.dll'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high
regression_tests_path: regression_data/rules/windows/image_load/image_load_win_susp_dbgcore_dbghelp_load/info.yml

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://blog.axelarator.net/hunting-for-edr-freeze/
• https://www.zerosalarium.com/2025/09/EDR-Freeze-Puts-EDRs-Antivirus-Into-Coma.html
• https://www.splunk.com/en_us/blog/security/you-bet-your-lsass-hunting-lsass-access.html