A kernel module was added to /lib/modules/

Overview

Goal

Kernel modules can be used to automatically execute code when a host starts up. Attackers sometimes use kernel modules to gain persistence on a particular host, ensuring that their code is executed even after a system reboot. Kernel modules also can help attackers gain elevated permissions on a system.

Strategy

Kernel modules are loaded from the /lib/modules directory in Linux. This detection watches for all new files created under that directory.

Triage & Response

1. Check the name of the new kernel module created.
2. Check which user or process created the module.
3. If the new kernel module is not expected, contain the host or container, and roll back to a known good configuration.