Windows Security: checkadmin.exe TargetUserName starting with Administr (Event ID 4799)
Detects Windows Security Event 4799 where checkadmin.exe targets “Administr*” accounts, consistent with admin account enumeration.
- Product
- windows
- Service
- security
- Author
- Florian Roth (Nextron Systems), frack113 (SigmaHQ), DRL 1.1
- Published
- 2019-12-20
- Updated
- 2026-07-31
ATT&CK techniques
Execution → DiscoveryRecon
Resource Dev
Initial Access
Persistence
Priv Esc
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule flags Windows Security events (Event ID 4799) where the TargetUserName begins with "Administr" and the CallerProcessName ends with "\checkadmin.exe". Such activity can indicate attempts to discover or enumerate local administrator accounts, which is useful for follow-on privilege escalation and persistence. It relies on Windows Security auditing telemetry that records the caller process and the target account involved in the operation.
Reporting behind it
- web.archive.orghttps://web.archive.org/web/20200226212615/https://www.fox-it.com/en/news/whitepapers/operation-wocao-shining-a-light-on-one-of-chinas-hidden-hacking-groups/
- web.archive.orghttps://web.archive.org/web/20200226212615/https://resources.fox-it.com/rs/170-CAK-271/images/201912_Report_Operation_Wocao.pdf
- twitter.comhttps://twitter.com/SBousseaden/status/1207671369963646976
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2019/TA/Operation-Wocao/win_security_apt_wocao.yml
Changelog
v5- v5Candidate ingested via manual entry.2026-07-31
- v4Candidate ingested via manual entry.2026-07-31
- v3Candidate ingested via manual entry.2026-07-31
- v2Candidate ingested via manual entry.2026-07-31
- v1No changelog recorded for this version.2026-07-30
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: "Windows Security: checkadmin.exe TargetUserName starting with Administr (Event ID 4799)"
id: c54e7de0-9c7a-442f-814f-f18cda0d2aca
status: test
description: This rule flags Windows Security events (Event ID 4799) where the TargetUserName begins with "Administr" and the CallerProcessName ends with "\checkadmin.exe". Such activity can indicate attempts to discover or enumerate local administrator accounts, which is useful for follow-on privilege escalation and persistence. It relies on Windows Security auditing telemetry that records the caller process and the target account involved in the operation.
references:
- https://web.archive.org/web/20200226212615/https://www.fox-it.com/en/news/whitepapers/operation-wocao-shining-a-light-on-one-of-chinas-hidden-hacking-groups/
- https://web.archive.org/web/20200226212615/https://resources.fox-it.com/rs/170-CAK-271/images/201912_Report_Operation_Wocao.pdf
- https://twitter.com/SBousseaden/status/1207671369963646976
- https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2019/TA/Operation-Wocao/win_security_apt_wocao.yml
author: Florian Roth (Nextron Systems), frack113, Huntrule Team
date: 2019-12-20
modified: 2022-11-27
tags:
- attack.privilege-escalation
- attack.persistence
- attack.discovery
- attack.stealth
- attack.t1012
- attack.t1036.004
- attack.t1027
- attack.execution
- attack.t1053.005
- attack.t1059.001
- detection.emerging-threats
logsource:
product: windows
service: security
detection:
selection:
EventID: 4799
TargetUserName|startswith: Administr
CallerProcessName|endswith: \checkadmin.exe
condition: selection
falsepositives:
- Administrators that use checkadmin.exe tool to enumerate local administrators
level: high
license: DRL-1.1
related:
- id: 74ad4314-482e-4c3e-b237-3f7ed3b9ca8d
type: derived