Sigma rule: Suspicious Renamed Comsvcs DLL Loaded By Rundll32

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-f8d2eccb11b9, updated 2023-02-17T00:00:00.000Z.

Rule

Title
Suspicious Renamed Comsvcs DLL Loaded By Rundll32
Status
test
Level
high
Author
Nasreddine Bencherchali (Nextron Systems)
Date
2022-08-14
Modified
2023-02-17
File
rules/windows/image_load/image_load_dll_comsvcs_load_renamed_version_by_rundll32.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects rundll32 loading a renamed comsvcs.dll to dump process memory

Log source

product
windows
category
image_load

Detection

selection:
    Image|endswith: '\rundll32.exe'
    Hashes|contains:
        # Add more hashes for other windows versions
        - IMPHASH=eed93054cb555f3de70eaa9787f32ebb # Windows 11 21H2 x64
        - IMPHASH=5e0dbdec1fce52daae251a110b4f309d # Windows 10 1607
        - IMPHASH=eadbccbb324829acb5f2bbe87e5549a8 # Windows 10 1809
        - IMPHASH=407ca0f7b523319d758a40d7c0193699 # Windows 10 2004 x64
        - IMPHASH=281d618f4e6271e527e6386ea6f748de # Windows 10 2004 x86
filter:
    ImageLoaded|endswith: '\comsvcs.dll'
condition: selection and not filter

False positives (as the rule lists them)

  • Unlikely

Tags

  • attack.credential-access
  • attack.t1003.001

MITRE ATT&CK ids this rule names

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/windows/image_load/image_load_dll_comsvcs_load_renamed_version_by_rundll32.yml

Sources and licences

  • SigmaHQ

    "Suspicious Renamed Comsvcs DLL Loaded By Rundll32" by Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/image_load/image_load_dll_comsvcs_load_renamed_version_by_rundll32.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: Suspicious Renamed Comsvcs DLL Loaded By Rundll32",
entity page, dataset version ref-f8d2eccb11b9, updated 2023-02-17T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/8cde342c-ba48-4b74-b615-172c330f2e93 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 8cde342c-ba48-4b74-b615-172c330f2e93, 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.