Create or Modify System Process

Adversaries may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence. When operating systems boot up, they can start processes that perform background system functions. On Windows and Linux, these system processes are referred to as services.[1] On macOS, launchd processes known as Launch Daemon and Launch Agent are run to finish system initialization and load user specific parameters.[2]

Adversaries may install new services, daemons, or agents that can be configured to execute at startup or a repeatable interval in order to establish persistence. Similarly, adversaries may modify existing services, daemons, or agents to achieve the same effect.

Services, daemons, or agents may be created with administrator privileges but executed under root/SYSTEM privileges. Adversaries may leverage this functionality to create or modify system processes in order to escalate privileges.[3]

ID: T1543
Sub-techniques:  T1543.001, T1543.002, T1543.003, T1543.004
Platforms: Linux, Windows, macOS
Version: 1.1
Created: 10 January 2020
Last Modified: 20 April 2022

Procedure Examples

ID Name Description
S0401 Exaramel for Linux

Exaramel for Linux has a hardcoded location that it uses to achieve persistence if the startup system is Upstart or System V and it is running as root.[4]

Mitigations

ID Mitigation Description
M1047 Audit

Use auditing tools capable of detecting privilege and service abuse opportunities on systems within an enterprise and correct them.

M1040 Behavior Prevention on Endpoint

On Windows 10, enable Attack Surface Reduction (ASR) rules to prevent an application from writing a signed vulnerable driver to the system.[5] On Windows 10 and 11, enable Microsoft Vulnerable Driver Blocklist to assist in hardening against third party-developed drivers.[6]

M1045 Code Signing

Enforce registration and execution of only legitimately signed service drivers where possible.

M1033 Limit Software Installation

Restrict software installation to trusted repositories only and be cautious of orphaned software packages.

M1028 Operating System Configuration

Ensure that Driver Signature Enforcement is enabled to restrict unsigned drivers from being installed.

M1022 Restrict File and Directory Permissions

Restrict read/write access to system-level process files to only select privileged users who have a legitimate need to manage system services.

M1018 User Account Management

Limit privileges of user accounts and groups so that only authorized administrators can interact with system-level process changes and service configurations.

Detection

ID Data Source Data Component Detects
DS0017 Command Command Execution

Command-line invocation of tools capable of modifying services may be unusual, depending on how systems are typically used in a particular environment. Look for abnormal process call trees from known services and for execution of other commands that could relate to Discovery or other adversary techniques.

DS0027 Driver Driver Load

Monitor for new service driver installations and loads (ex: Sysmon Event ID 6) that are not part of known software update/patch cycles.

DS0022 File File Creation

Monitor for newly constructed files that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

File Modification

Monitor for changes to files associated with system-level processes.

DS0009 Process OS API Execution

Monitor for API calls that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

Process Creation

New, benign system processes may be created during installation of new software.

DS0019 Service Service Creation

Monitor for newly constructed services/daemons that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

Service Modification

Monitor for changes to system processes that do not correlate with known software, patch cycles, etc., including by comparing results against a trusted system baseline.

DS0024 Windows Registry Windows Registry Key Creation

Monitor for newly constructed windows registry keys that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

Windows Registry Key Modification

Monitor for changes to windows registry keys and/or values that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

References