Sigma rule: Suspicious Loading of Dbgcore/Dbghelp DLLs from Uncommon Location

Rule

Title

Suspicious Loading of Dbgcore/Dbghelp DLLs from Uncommon Location

Status

experimental

Level

high

Author

Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2025-11-27

Modified

2026-01-09

File

rules/windows/image_load/image_load_win_susp_dbgcore_dbghelp_load.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product

windows

category

image_load

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_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.credential-access
• attack.defense-impairment
• attack.t1003
• attack.t1685

MITRE ATT&CK ids this rule names

• T1003
• T1685

Related rules

• 9f5c1d59-33be-4e60-bcab-85d2f566effd (similar)

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

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