UAC Bypass via DiskCleanup Scheduled Task Hijack

Elastic Stack Serverless Security

Identifies User Account Control (UAC) bypass via hijacking DiskCleanup Scheduled Task. Attackers bypass UAC to stealthily execute code with elevated permissions.

Rule type: eql

Rule indices:

• winlogbeat-*
• logs-endpoint.events.*
• logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Privilege Escalation

Version: 101

Rule authors:

• Elastic

Rule license: Elastic License v2

process where event.type == "start" and
 process.args : "/autoclean" and process.args : "/d" and
 not process.executable : ("C:\\Windows\\System32\\cleanmgr.exe",
                           "C:\\Windows\\SysWOW64\\cleanmgr.exe",
                           "C:\\Windows\\System32\\taskhostw.exe")

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Privilege Escalation
  • ID: TA0004
  • Reference URL: https://attack.mitre.org/tactics/TA0004/

• Technique:

  • Name: Abuse Elevation Control Mechanism
  • ID: T1548
  • Reference URL: https://attack.mitre.org/techniques/T1548/

• Sub-technique:

  • Name: Bypass User Account Control
  • ID: T1548.002
  • Reference URL: https://attack.mitre.org/techniques/T1548/002/