LoFP LoFP / legitimate python developers or system administrators may modify pythonpath for testing or application configuration purposes. filter based on known development environments and trusted user activity.

Techniques

Sample rules

Linux Possible Privilege Escalation via PYTHONPATH

Description

The following analytic detects the creation of a malicious shared object at a Python importlib path outside the standard system library directories, a technique used to abuse PYTHONPATH for local privilege escalation. Attackers exploiting vulnerabilities such as the 2024 NeedRestart flaw (CVE-2024-48990) plant a crafted importlib/init.so in an attacker-controlled directory, then manipulate the PYTHONPATH environment variable so that a privileged process, such as NeedRestart running as root, loads the rogue module instead of the legitimate one, achieving code execution with elevated privileges. The detection monitors for file writes matching the importlib/init.so pattern that do not originate from expected system library paths.

Detection logic


| tstats `security_content_summariesonly`
  count min(_time) as firstTime
        max(_time) as lastTime

from datamodel=Endpoint.Filesystem where

Filesystem.file_path="*/importlib/__init__.so*"
NOT Filesystem.file_path IN (
    "/lib/*",
    "/lib64/*",
    "/usr/lib/*",
    "/usr/lib64/*",
    "/usr/local/lib/*",
    "/usr/local/lib64/*"
)

by Filesystem.file_path Filesystem.file_name Filesystem.user Filesystem.dest
   Filesystem.process_guid Filesystem.process_id


| `drop_dm_object_name(Filesystem)`

| `security_content_ctime(firstTime)`

| `security_content_ctime(lastTime)`

| `linux_possible_privilege_escalation_via_pythonpath_filter`