IMPORTANT: No additional bug fixes or documentation updates will be released for this version. For the latest information, see the current release documentation.
« UAC Bypass Attempt with IEditionUpgradeManager Elevated COM Interface UAC Bypass via ICMLuaUtil Elevated COM Interface »
Elastic Docs ›Elastic Security Solution [8.2] ›Detections and alerts ›Prebuilt rule reference

UAC Bypass via DiskCleanup Scheduled Task Hijack

edit

UAC Bypass via DiskCleanup Scheduled Task Hijack

edit

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: 5 minutes

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

Maximum alerts per execution: 100

Tags:

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

Version: 7 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 8.2.0

Rule authors: Elastic

Rule license: Elastic License v2

Investigation guide

edit
## Config

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

Rule query

edit
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")

Threat mapping

edit

Framework: MITRE ATT&CKTM

Rule version history

edit
Version 7 (8.2.0 release)
  • Formatting only
Version 6 (7.15.0 release)
  • Formatting only
Version 5 (7.13.0 release)

  • Updated query, changed from:

    process where event.type in ("start", "process_started") and
process.args:"/autoclean" and process.args:"/d" and not
process.executable : ("C:\\Windows\\System32\\cleanmgr.exe",
"C:\\Windows\\SysWOW64\\cleanmgr.exe")
Version 4 (7.12.0 release)
  • Formatting only
Version 3 (7.11.2 release)
  • Formatting only
Version 2 (7.11.0 release)

  • Updated query, changed from:

    event.category:process and event.type:(start or process_started) and
process.args:(/autoclean or /AUTOCLEAN) and
process.parent.name:svchost.exe and not
process.executable:("C:\Windows\System32\cleanmgr.exe" or
"C:\Windows\SysWOW64\cleanmgr.exe")
« UAC Bypass Attempt with IEditionUpgradeManager Elevated COM Interface UAC Bypass via ICMLuaUtil Elevated COM Interface »