t1053-006-systemd-timers

name	T1053.006_systemd-timers
description	Adversaries may abuse systemd timers to perform task scheduling for initial or recurring execution of malicious code.
category	input-validation
version	18.1
author	cyberstrike-official
tags	["mitre-attack","enterprise","t1053.006","execution","persistence","privilege-escalation","linux","sub-technique"]
technique_id	T1053.006
tactic	execution
all_tactics	["execution","persistence","privilege-escalation"]
platforms	["Linux"]
mitre_url	https://attack.mitre.org/techniques/T1053/006
tech_stack	["linux"]
cwe_ids	["CWE-94"]
chains_with	["T1053","T1053.002","T1053.003","T1053.005","T1053.007"]
prerequisites	["T1053"]
severity_boost	{"T1053":"Chain with T1053 for deeper attack path","T1053.002":"Chain with T1053.002 for deeper attack path","T1053.003":"Chain with T1053.003 for deeper attack path"}

T1053.006 Systemd Timers

Sub-technique of: T1053

High-Level Description

Adversaries may abuse systemd timers to perform task scheduling for initial or recurring execution of malicious code. Systemd timers are unit files with file extension .timer that control services. Timers can be set to run on a calendar event or after a time span relative to a starting point. They can be used as an alternative to Cron in Linux environments. Systemd timers may be activated remotely via the systemctl command line utility, which operates over SSH.

Each .timer file must have a corresponding .service file with the same name, e.g., example.timer and example.service. .service files are Systemd Service unit files that are managed by the systemd system and service manager. Privileged timers are written to /etc/systemd/system/ and /usr/lib/systemd/system while user level are written to ~/.config/systemd/user/.

An adversary may use systemd timers to execute malicious code at system startup or on a scheduled basis for persistence. Timers installed using privileged paths may be used to maintain root level persistence. Adversaries may also install user level timers to achieve user level persistence.

Kill Chain Phase

• Execution (TA0002)
• Persistence (TA0003)
• Privilege Escalation (TA0004)

Platforms: Linux

What to Check

• Identify if Systemd Timers technique is applicable to target environment
• Check Linux systems for indicators of Systemd Timers
• Verify mitigations are bypassed or absent (3 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test

Atomic Red Team Tests

The following tests are from Atomic Red Team and provide actionable ways to test this technique:

Atomic Test 1: Create Systemd Service and Timer

This test creates Systemd service and timer then starts and enables the Systemd timer

Supported Platforms: linux Elevation Required: Yes