Elastic Security Detection Rules

Potential Linux Backdoor User Account Creation

Last updated 5 months ago on 2025-03-20
Created 2 years ago on 2023-03-07

About

Identifies the attempt to create a new backdoor user by setting the user's UID to 0. Attackers may alter a user's UID to 0 to establish persistence on a system.
Tags
Domain: EndpointOS: LinuxUse Case: Threat DetectionTactic: PersistenceData Source: Elastic EndgameData Source: Elastic DefendData Source: Auditd ManagerData Source: CrowdstrikeData Source: SentinelOneLanguage: eql
Severity
medium
Risk Score
47
MITRE ATT&CK™

Persistence (TA0003)(opens in a new tab or window)

↳ Create Account (T1136)(opens in a new tab or window)

License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
auditbeat-*endgame-*logs-auditd_manager.auditd-*logs-crowdstrike.fdr*logs-endpoint.events.process*logs-sentinel_one_cloud_funnel.*
Related Integrations

endpoint(opens in a new tab or window)

auditd_manager(opens in a new tab or window)

crowdstrike(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

Query
process where host.os.type == "linux" and event.type == "start" and
 event.action in ("exec", "exec_event", "start", "ProcessRollup2", "executed", "process_started")
 and process.name == "usermod" and process.args : "-u" and process.args : "0" and process.args : "-o"

Install detection rules in Elastic Security

Detect Potential Linux Backdoor User Account Creation in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).