Windows Security: Suspicious Local Account Created with ANONYMOUS LOGON SamAccountName

Alerts on Windows local account creation where the new SamAccountName contains “ANONYMOUS” and “LOGON”.

FreeReviewedSigma · High · v2

Product: windows
Service: security
Author: James Pemberton / @4A616D6573 (SigmaHQ), DRL 1.1
Published: 2019-10-31
Updated: 2026-07-31

ATT&CK techniques

Persistence

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1136.001Local Account
- T1136.002Domain Account
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags Windows Security EventID 4720 when a new local account is created with a SamAccountName containing both "ANONYMOUS" and "LOGON". Attackers may attempt to mimic or blend into system-like naming to support persistence or evasion. Detection relies on account creation telemetry from Windows Security logs, specifically the new account name field in EventID 4720.

Reporting behind it

Related detections9 linkedT1136.001 — drag to rearrange

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Suspicious Local Administrator Account Creation via Net Command via Process Creation (via process_creation)

Suspicious Rogue Machine Account Creation via Powermad New-MachineAccount

Malicious Local Administrator Account Added via net localgroup (via process_creation)

Malicious Switch User to Rogue Root-Equivalent Account troot (via process_creation)

Malicious Rogue F5 BIG-IP Administrator Account Creation via tmsh (via process_creation)

Windows Security: Suspicious Local Account Created with ANONYMOUS LOGON SamAccountName

Pivot detection · T1136.001 · 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-suspicious-local-account-creation-with-anonymous-logon-account--1bbf25b9

title: "Windows Security: Suspicious Local Account Created with ANONYMOUS LOGON SamAccountName"
id: 481553c6-0952-40e1-97af-0645c7ece9f6
status: test
description: This rule flags Windows Security EventID 4720 when a new local account is created with a SamAccountName containing both "ANONYMOUS" and "LOGON". Attackers may attempt to mimic or blend into system-like naming to support persistence or evasion. Detection relies on account creation telemetry from Windows Security logs, specifically the new account name field in EventID 4720.
references:
  - https://twitter.com/SBousseaden/status/1189469425482829824
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_susp_local_anon_logon_created.yml
author: James Pemberton / @4A616D6573, Huntrule Team
date: 2019-10-31
modified: 2022-10-09
tags:
  - attack.persistence
  - attack.t1136.001
  - attack.t1136.002
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 4720
    SamAccountName|contains|all:
      - ANONYMOUS
      - LOGON
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: 1bbf25b9-8038-4154-a50b-118f2a32be27
    type: derived

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