Sigma rule: Process Memory Dump Via Comsvcs.DLL

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-5811d7d75cdf, updated 2025-02-23T00:00:00.000Z.

Rule

Title
Process Memory Dump Via Comsvcs.DLL
Status
test
Level
high
Author
Florian Roth (Nextron Systems), Modexp, Nasreddine Bencherchali (Nextron Systems), Swachchhanda Shrawan Poudel (Nextron Systems)
Date
2020-02-18
Modified
2025-02-23
File
rules/windows/process_creation/proc_creation_win_rundll32_process_dump_via_comsvcs.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a process memory dump via "comsvcs.dll" using rundll32, covering multiple different techniques (ordinal, minidump function, etc.)

Log source

product
windows
category
process_creation

Detection

selection_img:
    - Image|endswith: '\rundll32.exe'
    - OriginalFileName: 'RUNDLL32.EXE'
    - CommandLine|contains: 'rundll32'
selection_cli_1:
    CommandLine|contains|all:
        - 'comsvcs'
        - 'full'
    CommandLine|contains:
        - '#-'
        - '#+'
        - '#24'
        - '24 '
        - 'MiniDump' # Matches MiniDump and MinidumpW
        - '#65560' # ordinal is 16 bit ordinal, so if you make the number large enough (don't fit in 16 bit space), then it normally wraps around.  for e.g ordinal 24 can be also represented by 65560 (65536+24)
selection_generic:
    CommandLine|contains|all:
        - '24'
        - 'comsvcs'
        - 'full'
    CommandLine|contains:
        - ' #'
        - ',#'
        - ', #'
        - '"#'
condition: (selection_img and 1 of selection_cli_*) or selection_generic

False positives (as the rule lists them)

  • Unlikely

Tags

  • attack.credential-access
  • attack.stealth
  • attack.t1036
  • attack.t1003.001
  • car.2013-05-009

MITRE ATT&CK ids this rule names

Related rules

  • 09e6d5c0-05b8-4ff8-9eeb-043046ec774c (obsolete)

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_rundll32_process_dump_via_comsvcs.yml

Sources and licences

  • SigmaHQ

    "Process Memory Dump Via Comsvcs.DLL" by Florian Roth (Nextron Systems), Modexp, Nasreddine Bencherchali (Nextron Systems), Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_rundll32_process_dump_via_comsvcs.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: Process Memory Dump Via Comsvcs.DLL",
entity page, dataset version ref-5811d7d75cdf, updated 2025-02-23T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/646ea171-dded-4578-8a4d-65e9822892e3 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 646ea171-dded-4578-8a4d-65e9822892e3, 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.