Server Software Component

Adversaries may abuse legitimate extensible development features of servers to establish persistent access to systems. Enterprise server applications may include features that allow developers to write and install software or scripts to extend the functionality of the main application. Adversaries may install malicious components to extend and abuse server applications.[1]

ID: T1505
Tactic: Persistence
Platforms: Linux, Network, Windows, macOS
Version: 1.4
Created: 28 June 2019
Last Modified: 19 October 2022

Mitigations

ID Mitigation Description
M1047 Audit

Regularly check component software on critical services that adversaries may target for persistence to verify the integrity of the systems and identify if unexpected changes have been made.

M1045 Code Signing

Ensure all application component binaries are signed by the correct application developers.

M1042 Disable or Remove Feature or Program

Consider disabling software components from servers when possible to prevent abuse by adversaries.[2]

M1026 Privileged Account Management

Do not allow administrator accounts that have permissions to add component software on these services to be used for day-to-day operations that may expose them to potential adversaries on unprivileged systems.

M1024 Restrict Registry Permissions

Consider using Group Policy to configure and block modifications to service and other critical server parameters in the Registry.[3]

M1018 User Account Management

Enforce the principle of least privilege by limiting privileges of user accounts so only authorized accounts can modify and/or add server software components.[4]

Detection

ID Data Source Data Component Detects
DS0015 Application Log Application Log Content

Monitor for third-party application logging, messaging, and/or other artifacts that may abuse legitimate extensible development features of servers to establish persistent access to systems. Consider monitoring application logs for abnormal behavior that may indicate suspicious installation of application software components. Log authentication attempts to the server and any unusual traffic patterns to or from the server and internal network. [5]

DS0022 File File Creation

Consider monitoring file locations associated with the installation of new application software components such as paths from which applications typically load such extensible components.

File Modification

Monitor for changes made to files that may abuse legitimate extensible development features of servers to establish persistent access to systems.

DS0029 Network Traffic Network Traffic Content

Monitor and analyze traffic patterns and packet inspection associated to protocol(s), leveraging SSL/TLS inspection for encrypted traffic, that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). [5]

Network Traffic Flow

Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.

DS0009 Process Process Creation

Process monitoring may be used to detect servers components that perform suspicious actions such as running cmd.exe or accessing files.

References