Sigma rule: WerFaultSecure Loading DbgCore or DbgHelp - EDR-Freeze

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-980c0b0a5bcd, updated 2026-01-09T00:00:00.000Z.

Rule

Title
WerFaultSecure Loading DbgCore or DbgHelp - EDR-Freeze
Status
experimental
Level
medium
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Date
2025-11-27
Modified
2026-01-09
File
rules-threat-hunting/windows/image_load/image_load_win_werfaultsecure_dbgcore_dbghelp_load.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the loading of dbgcore.dll or dbghelp.dll by WerFaultSecure.exe, which has been observed in EDR-Freeze attacks to suspend processes and evade detection.
However, this behavior has also been observed during normal software installations, so further investigation is required to confirm malicious activity.
When threat hunting, look for this activity in conjunction with other suspicious processes starting, network connections, or file modifications that occur shortly after the DLL load.
Pay special attention to timing - if other malicious activities occur during or immediately after this library loading, it may indicate EDR evasion attempts.
Also correlate with any EDR/AV process suspension events or gaps in security monitoring during the timeframe.

Log source

product
windows
category
image_load

Detection

selection:
    Image|endswith: '\WerFaultSecure.exe'
    ImageLoaded|endswith:
        - '\dbgcore.dll'
        - '\dbghelp.dll'
condition: selection

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.defense-impairment
  • attack.t1685
  • detection.threat-hunting

MITRE ATT&CK ids this rule names

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-threat-hunting/windows/image_load/image_load_win_werfaultsecure_dbgcore_dbghelp_load.yml

Sources and licences

  • SigmaHQ

    "WerFaultSecure Loading DbgCore or DbgHelp - EDR-Freeze" by Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-threat-hunting/windows/image_load/image_load_win_werfaultsecure_dbgcore_dbghelp_load.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: WerFaultSecure Loading DbgCore or DbgHelp - EDR-Freeze",
entity page, dataset version ref-980c0b0a5bcd, updated 2026-01-09T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/8a2f4b1c-3d5e-4f7a-9b2c-1e4f6d8a9c2b (accessed 2026-11-03).
Underlying source: SigmaHQ rule 8a2f4b1c-3d5e-4f7a-9b2c-1e4f6d8a9c2b, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.