Sigma rule: Suspicious NTLM Authentication on the Printer Spooler Service

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-9283aea636c4, updated 2023-02-09T00:00:00.000Z.

Rule

Title
Suspicious NTLM Authentication on the Printer Spooler Service
Status
test
Level
high
Author
Elastic (idea), Tobias Michalski (Nextron Systems)
Date
2022-05-04
Modified
2023-02-09
File
rules/windows/process_creation/proc_creation_win_rundll32_ntlmrelay.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a privilege elevation attempt by coercing NTLM authentication on the Printer Spooler service

Log source

product
windows
category
process_creation

Detection

selection_img:
    - Image|endswith: '\rundll32.exe'
    - OriginalFileName: 'RUNDLL32.EXE'
selection_cli:
    CommandLine|contains|all:
        - 'C:\windows\system32\davclnt.dll,DavSetCookie'
        - 'http'
    CommandLine|contains:
        - 'spoolss'
        - 'srvsvc'
        - '/print/pipe/'
condition: all of selection_*

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.privilege-escalation
  • attack.credential-access
  • attack.t1212

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/process_creation/proc_creation_win_rundll32_ntlmrelay.yml

Sources and licences

  • SigmaHQ

    "Suspicious NTLM Authentication on the Printer Spooler Service" by Elastic (idea), Tobias Michalski (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_rundll32_ntlmrelay.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 NTLM Authentication on the Printer Spooler Service",
entity page, dataset version ref-9283aea636c4, updated 2023-02-09T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/bb76d96b-821c-47cf-944b-7ce377864492 (accessed 2026-11-03).
Underlying source: SigmaHQ rule bb76d96b-821c-47cf-944b-7ce377864492, 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.