Sigma rule: Potential Renamed Rundll32 Execution

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-fc22caf2a0a3, updated 2023-02-03T00:00:00.000Z.

Rule

Title
Potential Renamed Rundll32 Execution
Status
test
Level
high
Author
Nasreddine Bencherchali (Nextron Systems)
Date
2022-08-22
Modified
2023-02-03
File
rules/windows/process_creation/proc_creation_win_renamed_rundll32_dllregisterserver.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects when 'DllRegisterServer' is called in the commandline and the image is not rundll32. This could mean that the 'rundll32' utility has been renamed in order to avoid detection

Log source

product
windows
category
process_creation

Detection

selection:
    CommandLine|contains: 'DllRegisterServer'
filter:
    Image|endswith: '\rundll32.exe'
condition: selection and not filter

False positives (as the rule lists them)

  • Unlikely

Tags

  • attack.execution

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/windows/process_creation/proc_creation_win_renamed_rundll32_dllregisterserver.yml

Sources and licences

  • SigmaHQ

    "Potential Renamed Rundll32 Execution" by Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_renamed_rundll32_dllregisterserver.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: Potential Renamed Rundll32 Execution",
entity page, dataset version ref-fc22caf2a0a3, updated 2023-02-03T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/2569ed8c-1147-498a-9b8c-2ad3656b10ed (accessed 2026-11-03).
Underlying source: SigmaHQ rule 2569ed8c-1147-498a-9b8c-2ad3656b10ed, 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.