Detection rules › Sigma
Creation Of An User Account
Detects the creation of a new user account. Such accounts may be used for persistence that do not require persistent remote access tools to be deployed on the system.
Known false positives
- Admin activity
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence |
Telemetry coverage
| Platform | Record / event type |
|---|---|
| Linux | auditd ADD_USER record: User account added |
| Linux | auditd SYSCALL record: System call event information |
Rule body
title: Creation Of An User Account
id: 759d0d51-bc99-4b5e-9add-8f5b2c8e7512
status: test
description: Detects the creation of a new user account. Such accounts may be used for persistence that do not require persistent remote access tools to be deployed on the system.
references:
- https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/security_guide/sec-understanding_audit_log_files
- https://access.redhat.com/articles/4409591#audit-record-types-2
- https://www.youtube.com/watch?v=VmvY5SQm5-Y&ab_channel=M45C07
author: Marie Euler, Pawel Mazur
date: 2020-05-18
modified: 2022-12-20
tags:
- attack.t1136.001
- attack.persistence
logsource:
product: linux
service: auditd
detection:
selection_syscall_record_type:
type: 'SYSCALL'
exe|endswith: '/useradd'
selection_add_user_record_type:
type: 'ADD_USER' # This is logged without having to configure audit rules on both Ubuntu and Centos
condition: 1 of selection_*
falsepositives:
- Admin activity
level: medium
Stages and Predicates
Stage 0: condition
1 of selection_*Stage 1: selection_syscall_record_type
selection_syscall_record_type:
type: 'SYSCALL'
exe|endswith: '/useradd'
Stage 2: selection_add_user_record_type
selection_add_user_record_type:
type: 'ADD_USER'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
exe | ends_with |
| field:"exe" kind:ends_with value:"/useradd" |
type | eq |
| field:"type" kind:eq |