Sigma rule: Potentially Suspicious Execution Of Regasm/Regsvcs With Uncommon Extension

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-e368cb7cb3a1, updated 2023-02-13T00:00:00.000Z.

Rule

Title
Potentially Suspicious Execution Of Regasm/Regsvcs With Uncommon Extension
Status
test
Level
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Date
2023-02-13
File
rules/windows/process_creation/proc_creation_win_regasm_regsvcs_uncommon_extension_execution.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects potentially suspicious execution of the Regasm/Regsvcs utilities with an uncommon extension.

Log source

product
windows
category
process_creation

Detection

selection_img:
    - Image|endswith:
          - '\Regsvcs.exe'
          - '\Regasm.exe'
    - OriginalFileName:
          - 'RegSvcs.exe'
          - 'RegAsm.exe'
selection_extension:
    CommandLine|contains:
        # Note: Add more potentially uncommon extensions
        - '.dat'
        - '.gif'
        - '.jpeg'
        - '.jpg'
        - '.png'
        - '.txt'
condition: all of selection_*

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.stealth
  • attack.t1218.009

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/windows/process_creation/proc_creation_win_regasm_regsvcs_uncommon_extension_execution.yml

Sources and licences

  • SigmaHQ

    "Potentially Suspicious Execution Of Regasm/Regsvcs With Uncommon Extension" by Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_regasm_regsvcs_uncommon_extension_execution.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: Potentially Suspicious Execution Of Regasm/Regsvcs With Uncommon Extension",
entity page, dataset version ref-e368cb7cb3a1, updated 2023-02-13T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/e9f8f8cc-07cc-4e81-b724-f387db9175e4 (accessed 2026-11-03).
Underlying source: SigmaHQ rule e9f8f8cc-07cc-4e81-b724-f387db9175e4, 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.