Sigma rule: Suspicious Computer Account Name Change CVE-2021-42287

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-693917da5273, updated 2022-12-25T00:00:00.000Z.

Rule

Title
Suspicious Computer Account Name Change CVE-2021-42287
Status
test
Level
high
Author
Florian Roth (Nextron Systems)
Date
2021-12-22
Modified
2022-12-25
File
rules-emerging-threats/2021/Exploits/CVE-2021-42287/win_security_samaccountname_spoofing_cve_2021_42287.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the renaming of an existing computer account to a account name that doesn't contain a $ symbol as seen in attacks against CVE-2021-42287

Log source

product
windows
service
security

Detection

selection:
    EventID: 4781 # rename user
    OldTargetUserName|contains: '$'
filter:
    NewTargetUserName|contains: '$'
condition: selection and not filter

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.privilege-escalation
  • attack.persistence
  • attack.stealth
  • attack.t1036
  • attack.t1098
  • cve.2021-42287
  • detection.emerging-threats

CVEs this rule names

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-emerging-threats/2021/Exploits/CVE-2021-42287/win_security_samaccountname_spoofing_cve_2021_42287.yml

Sources and licences

  • SigmaHQ

    "Suspicious Computer Account Name Change CVE-2021-42287" by Florian Roth (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-42287/win_security_samaccountname_spoofing_cve_2021_42287.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 Computer Account Name Change CVE-2021-42287",
entity page, dataset version ref-693917da5273, updated 2022-12-25T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/45eb2ae2-9aa2-4c3a-99a5-6e5077655466 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 45eb2ae2-9aa2-4c3a-99a5-6e5077655466, 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.