Elastic Security Detection Rules

Pluggable Authentication Module (PAM) Creation in Unusual Directory

Last updated 6 months ago on 2025-03-20
Created 9 months ago on 2024-12-16

About

This rule detects the creation of Pluggable Authentication Module (PAM) shared object files in unusual directories. Attackers may compile PAM shared object files in temporary directories, to move them to system directories later, potentially allowing them to maintain persistence on a compromised system, or harvest account credentials.
Tags
Domain: EndpointOS: LinuxUse Case: Threat DetectionTactic: Credential AccessTactic: PersistenceData Source: Elastic DefendData Source: SentinelOneData Source: Elastic EndgameLanguage: eql
Severity
low
Risk Score
21
MITRE ATT&CK™

Persistence (TA0003)(opens in a new tab or window)

↳ Create or Modify System Process (T1543)(opens in a new tab or window)

Credential Access (TA0006)(opens in a new tab or window)

↳ Modify Authentication Process (T1556)(opens in a new tab or window)

False Positive Examples
Trusted system module updates or allowed Pluggable Authentication Module (PAM) daemon configuration changes.
License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
logs-endpoint.events.file*logs-sentinel_one_cloud_funnel.*endgame-*
Related Integrations

endpoint(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

Query
file where host.os.type == "linux" and event.type == "creation" and file.name like "pam_*.so" and not file.path like (
  "/lib/security/*",
  "/lib64/security/*",
  "/lib/x86_64-linux-gnu/security/*",
  "/usr/lib/security/*",
  "/usr/lib64/security/*",
  "/usr/lib/x86_64-linux-gnu/security/*"
) and not (
  process.name in ("dockerd", "containerd", "steam", "buildkitd", "unsquashfs", "pacman") or
  file.path like (
    "/build/rootImage/nix/store/*", "/home/*/.local/share/containers/*", "/nix/store/*", "/var/lib/containerd/*",
    "/var/snap/*", "/usr/share/nix/nix/store/*", "/tmp/cura/squashfs-root/*", "/home/*/docker/*", "/tmp/containerd*"
  )
)

Install detection rules in Elastic Security

Detect Pluggable Authentication Module (PAM) Creation in Unusual Directory in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).