Detection rules › Sigma
Suspicious anonymous login (domain specified)
Detects scenarios where a suspicious anonymous login is performed during discovery phases.
Known false positives
- None
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Discovery |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Security-Auditing | Event ID 4624: An account was successfully logged on. |
Rule body
title: Suspicious anonymous login (domain specified)
description: Detects scenarios where a suspicious anonymous login is performed during discovery phases.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0007-Discovery/T1046-Network%20Service%20Scanning
- https://github.com/login-securite/DonPAPI
tags:
- attack.discovery
- attack.t1046
author: mdecrevoisier
status: experimental
logsource:
product: windows
service: security
detection:
selection:
EventID: 4624
TargetUserSid: S-1-5-7 # ANONYMOUS LOGON
LogonType: 3
AuthenticationPackageName: NTLM
filter:
- IpAddress:
- '%vulnerability_scanners%'
- TargetDomainName:
- 'NT AUTHORITY' # English
- 'AUTORITE NT' # French
- 'NT AUTHORITÄT' # German
#- other localized language names for the NT AUTHORITY
condition: selection and not filter
falsepositives:
- None
level: high
Stages and Predicates
Stage 0: condition
selection and not filterStage 1: selection
selection:
EventID: 4624
TargetUserSid: S-1-5-7
LogonType: 3
AuthenticationPackageName: NTLM
Stage 2: not filter
filter:
- IpAddress:
- '%vulnerability_scanners%'
- TargetDomainName:
- 'NT AUTHORITY'
- 'AUTORITE NT'
- 'NT AUTHORITÄT'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
IpAddress | eq | %vulnerability_scanners% | excludes:IpAddress field:"IpAddress" value:"%vulnerability_scanners%" |
TargetDomainName | eq | AUTORITE NT | excludes:TargetDomainName field:"TargetDomainName" value:"AUTORITE NT" |
TargetDomainName | eq | NT AUTHORITY | excludes:TargetDomainName field:"TargetDomainName" value:"NT AUTHORITY" |
TargetDomainName | eq | NT AUTHORITÄT | excludes:TargetDomainName field:"TargetDomainName" value:"NT AUTHORITÄT" |
Indicators
These rows show field, operator, and value matches.