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T1546.016 Installer Packages

Adversaries may establish persistence and elevate privileges by using an installer to trigger the execution of malicious content. Installer packages are OS specific and contain the resources an operating system needs to install applications on a system. Installer packages can include scripts that run prior to installation as well as after installation is complete. Installer scripts may inherit elevated permissions when executed. Developers often use these scripts to prepare the environment for installation, check requirements, download dependencies, and remove files after installation.6

Using legitimate applications, adversaries have distributed applications with modified installer scripts to execute malicious content. When a user installs the application, they may be required to grant administrative permissions to allow the installation. At the end of the installation process of the legitimate application, content such as macOS postinstall scripts can be executed with the inherited elevated permissions. Adversaries can use these scripts to execute a malicious executable or install other malicious components (such as a Launch Daemon) with the elevated permissions.1532

Depending on the distribution, Linux versions of package installer scripts are sometimes called maintainer scripts or post installation scripts. These scripts can include preinst, postinst, prerm, postrm scripts and run as root when executed.

For Windows, the Microsoft Installer services uses .msi files to manage the installing, updating, and uninstalling of applications. These installation routines may also include instructions to perform additional actions that may be abused by adversaries.4

Item Value
ID T1546.016
Sub-techniques T1546.001, T1546.002, T1546.003, T1546.004, T1546.005, T1546.006, T1546.007, T1546.008, T1546.009, T1546.010, T1546.011, T1546.012, T1546.013, T1546.014, T1546.015, T1546.016, T1546.017, T1546.018
Tactics TA0004, TA0003
Platforms Linux, Windows, macOS
Version 1.2
Created 27 September 2022
Last Modified 15 April 2025

Procedure Examples

ID Name Description
C0057 3CX Supply Chain Attack During the 3CX Supply Chain Attack, AppleJeus added a malicious .dylib file to a .dmg installer package for the macOS 3CX application.8
S0584 AppleJeus During AppleJeus’s installation process, it uses postinstall scripts to extract a hidden plist from the application’s /Resources folder and execute the plist file as a Launch Daemon with elevated permissions.7

References

  1. Brandon Dalton. (2022, August 9). A bundle of nerves: Tweaking macOS security controls to thwart application bundle manipulation. Retrieved September 27, 2022. ↩

  2. Debian Policy Manual v4.6.1.1. (2022, August 14). Package maintainer scripts and installation procedure. Retrieved September 27, 2022. ↩

  3. Global Research & Analysis Team, Kaspersky Lab (GReAT). (2018, August 23). Operation AppleJeus: Lazarus hits cryptocurrency exchange with fake installer and macOS malware. Retrieved September 27, 2022. ↩

  4. Microsoft. (2021, January 7). Installation Procedure Tables Group. Retrieved December 27, 2023. ↩

  5. Patrick Wardle. (2020, June 29). OSX.EvilQuest Uncovered part i: infection, persistence, and more!. Retrieved March 18, 2021. ↩

  6. Rich Trouton. (2019, August 9). Installer Package Scripting: Making your deployments easier, one ! at a time. Retrieved September 27, 2022. ↩

  7. Patrick Wardle. (2019, October 12). Pass the AppleJeus. Retrieved September 28, 2022. ↩

  8. Robert Falcone, Josh Grunzweig. (2023, March 30). Threat Brief: 3CXDesktopApp Supply Chain Attack. Retrieved September 15, 2025. ↩