Detection rules › Sigma
Suspicious computer account created by a computer account
Detects scenarios where an attacker abuse MachineAccountQuota privilege and pre-create a computer object for abusing RBCD delegation.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1136 Create Account |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4741 | A computer account was created. |
Rule body yaml
title: Suspicious computer account created by a computer account
description: Detects scenarios where an attacker abuse MachineAccountQuota privilege and pre-create a computer object for abusing RBCD delegation.
references:
- https://dirkjanm.io/worst-of-both-worlds-ntlm-relaying-and-kerberos-delegation/
tags:
- attack.persistence
- attack.t1136
author: mdecrevoisier
status: experimental
logsource:
product: windows
service: security
detection:
selection:
EventID: 4741
SubjectUserName|endswith: '$'
SubjectUserSid|startswith: 'S-1-5-21-' # SYSTEM account 'S-1-5-18' would trigger a false positive
TargetUserName|endswith: '$'
condition: selection
falsepositives:
- Offline domain join host
- Windows Autopilot Hybrid Azure AD Join
level: high
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
EventID: 4741
SubjectUserName|endswith: '$'
SubjectUserSid|startswith: 'S-1-5-21-'
TargetUserName|endswith: '$'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
SubjectUserName | ends_with |
|
SubjectUserSid | starts_with |
|
TargetUserName | ends_with |
|