Persistence via Update Orchestrator Service Hijack

Elastic Stack Serverless Security

Identifies potential hijacking of the Microsoft Update Orchestrator Service to establish persistence with an integrity level of SYSTEM.

Rule type: eql

Rule indices:

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

Severity: high

Risk score: 73

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:

• https://github.com/irsl/CVE-2020-1313

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Persistence

Version: 5

Rule authors:

• Elastic

Rule license: Elastic License v2

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.

process where event.type == "start" and
  process.parent.executable : "C:\\Windows\\System32\\svchost.exe" and
  process.parent.args : "UsoSvc" and
  not process.executable :
         (
          "C:\\Windows\\System32\\UsoClient.exe",
          "C:\\Windows\\System32\\MusNotification.exe",
          "C:\\Windows\\System32\\MusNotificationUx.exe",
          "C:\\Windows\\System32\\MusNotifyIcon.exe",
          "C:\\Windows\\System32\\WerFault.exe",
          "C:\\Windows\\System32\\WerMgr.exe"
          )

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Persistence
  • ID: TA0003
  • Reference URL: https://attack.mitre.org/tactics/TA0003/

• Technique:

  • Name: Create or Modify System Process
  • ID: T1543
  • Reference URL: https://attack.mitre.org/techniques/T1543/

• Sub-technique:

  • Name: Windows Service
  • ID: T1543.003
  • Reference URL: https://attack.mitre.org/techniques/T1543/003/