Windows Security 4611: Rubeus-Indicative New Trusted Logon Process Registration

Alerts on Windows Security Event 4611 registering a new trusted logon process named 'User32LogonProcesss'.

FreeReviewedSigma · High · v2

Product: windows
Service: security
Author: Roberto Rodriguez (source), Ilyas Ochkov (rule), oscd.community (SigmaHQ), DRL 1.1
Published: 2019-10-24
Updated: 2026-07-31

ATT&CK techniques

Cred Access

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
- T1558.003Kerberoasting
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags Windows Security events where a new trusted logon process is registered, specifically when the LogonProcessName matches 'User32LogonProcesss'. Attackers may leverage trusted logon process registration to enable credential access or lateral movement through established logon mechanisms. The detection relies on Windows Security auditing telemetry (Event ID 4611) with the registered logon process name.

Reporting behind it

Related detections9 linkedT1558.003 — drag to rearrange

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Suspicious Kerberoasting via setspn Service Principal Query

Masquerading Kerberos Ticket Abuse via Rubeus (via process_creation)

Possible Targeted Kerberoasting via servicePrincipalName Modification

Suspicious SQL Service Principal Name Enumeration via Setspn

Windows: Suspicious Kerberos Ticket Requests from PowerShell Using KerberosRequestorSecurityToken

Windows Process Creation: RemoteKrbRelay Kerberos Relay Tool Execution

Windows Kerberos KDC Key Distribution Failure: No Suitable Encryption Key or Unsupported EType

Rubeus HackTool Execution via PowerShell ScriptBlock Flags (Windows)

Windows Security 4611: Rubeus-Indicative New Trusted Logon Process Registration

Pivot detection · T1558.003 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No 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.

windows-security-event-4611-new-trusted-logon-process-via-user32logonprocesss-12e6d621

title: "Windows Security 4611: Rubeus-Indicative New Trusted Logon Process Registration"
id: 6fac1482-3f2d-4ffd-ba4f-c8619acf7e70
status: test
description: This rule flags Windows Security events where a new trusted logon process is registered, specifically when the LogonProcessName matches 'User32LogonProcesss'. Attackers may leverage trusted logon process registration to enable credential access or lateral movement through established logon mechanisms. The detection relies on Windows Security auditing telemetry (Event ID 4611) with the registered logon process name.
references:
  - https://posts.specterops.io/hunting-in-active-directory-unconstrained-delegation-forests-trusts-71f2b33688e1
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_register_new_logon_process_by_rubeus.yml
author: Roberto Rodriguez (source), Ilyas Ochkov (rule), oscd.community, Huntrule Team
date: 2019-10-24
modified: 2022-10-09
tags:
  - attack.lateral-movement
  - attack.privilege-escalation
  - attack.credential-access
  - attack.t1558.003
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 4611
    LogonProcessName: User32LogonProcesss
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: 12e6d621-194f-4f59-90cc-1959e21e69f7
    type: derived

Convert

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