Suspicious Kworker UID Elevation

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Monitors for the elevation of regular user permissions to root permissions through the kworker process. kworker, or kernel worker, processes are part of the kernel’s workqueue mechanism. They are responsible for executing work that has been scheduled to be done in kernel space, which might include tasks like handling interrupts, background activities, and other kernel-related tasks. Attackers may attempt to evade detection by masquerading as a kernel worker process, and hijack the execution flow by hooking certain functions/syscalls through a rootkit in order to provide easy access to root via a special modified command.

Rule type: eql

Rule indices:

  • logs-endpoint.events.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

  • Domain: Endpoint
  • OS: Linux
  • Use Case: Threat Detection
  • Tactic: Privilege Escalation
  • Tactic: Defense Evasion
  • Data Source: Elastic Defend

Version: 1

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

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process where host.os.type == "linux" and event.action == "session_id_change" and event.type == "change" and
process.name : "kworker*" and user.id == "0"

Framework: MITRE ATT&CKTM