Elastic Security Detection Rules

Initramfs Unpacking via unmkinitramfs

Last updated 9 days ago on 2025-01-22
Created 15 days ago on 2025-01-16

About

This rule detects the unpacking of an initramfs image using the `unmkinitramfs` command on Linux systems. The `unmkinitramfs` command is used to extract the contents of an initramfs image, which is used to boot the system. Attackers may use `unmkinitramfs` to unpack an initramfs image and modify its contents to include malicious code or backdoors, allowing them to maintain persistence on the system.
Tags
Domain: EndpointOS: LinuxUse Case: Threat DetectionTactic: PersistenceData Source: Elastic EndgameData Source: Elastic DefendData Source: Auditd ManagerData Source: CrowdstrikeData Source: SentinelOneLanguage: eql
Severity
low
Risk Score
21
MITRE ATT&CK™

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

↳ Pre-OS Boot (T1542)(opens in a new tab or window)

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

↳ Hijack Execution Flow (T1574)(opens in a new tab or window)

Execution (TA0002)(opens in a new tab or window)

↳ Command and Scripting Interpreter (T1059)(opens in a new tab or window)

Defense Evasion (TA0005)(opens in a new tab or window)

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.process*endgame-*auditbeat-*logs-auditd_manager.auditd-*logs-crowdstrike.fdr*logs-sentinel_one_cloud_funnel.*
Related Integrations

endpoint(opens in a new tab or window)

auditd_manager(opens in a new tab or window)

crowdstrike(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

Query
process where host.os.type == "linux" and event.type == "start" and
event.action in ("exec", "exec_event", "start", "ProcessRollup2", "executed") and
process.name == "unmkinitramfs"

Install detection rules in Elastic Security

Detect Initramfs Unpacking via unmkinitramfs 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).