Linux Detection Engineering - The Grand Finale on Linux Persistence Mechanisms

In the fifth and final part of the Linux Persistence Detection Engineering series, we bring the journey to its grand finale by exploring some of the most obscure, creative, and complex persistence mechanisms. Building on the foundational concepts covered in previous publications, this final installment focuses on techniques rooted in the Linux boot process, authentication systems, inter-process communication, and core utilities.

We begin with GRUB-based persistence and the manipulation of initramfs, demonstrating both manual modifications and automated approaches using Dracut. We then examine Polkit-based persistence, followed by an exploration of D-Bus exploitation, a lesser-known but powerful method for maintaining access. Finally, we dive into NetworkManager dispatcher scripts, showcasing how adversaries can leverage them for stealthy persistence.

Using PANIX, a Linux persistence tool I developed, we will simulate these techniques, analyze system logs, and uncover detection opportunities. By leveraging the tailored ES|QL and OSQuery queries provided, defenders can enhance their detection capabilities against even the most advanced persistence threats.

As we close this series, you’ll have gained in-depth knowledge of Linux persistence mechanisms—both common and highly evasive—along with the tools and strategies to detect and mitigate them effectively.

Are you interested in this research? The full paper is available at Elastic Security Labs!