Suspicious DLL Loaded for Persistence or Privilege Escalation

Elastic Stack Serverless Security

Identifies the loading of a non Microsoft signed DLL that is missing on a default Windows install (phantom DLL) or one that can be loaded from a different location by a native Windows process. This may be abused to persist or elevate privileges via privileged file write vulnerabilities.

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://itm4n.github.io/windows-dll-hijacking-clarified/
• http://remoteawesomethoughts.blogspot.com/2019/05/windows-10-task-schedulerservice.html
• https://googleprojectzero.blogspot.com/2018/04/windows-exploitation-tricks-exploiting.html
• https://shellz.club/2020/10/16/edgegdi-dll-for-persistence-and-lateral-movement.html
• https://windows-internals.com/faxing-your-way-to-system/
• http://waleedassar.blogspot.com/2013/01/wow64logdll.html

Tags:

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

Version: 4

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.

library where dll.name :
  (
  "wlbsctrl.dll",
  "wbemcomn.dll",
  "WptsExtensions.dll",
  "Tsmsisrv.dll",
  "TSVIPSrv.dll",
  "Msfte.dll",
  "wow64log.dll",
  "WindowsCoreDeviceInfo.dll",
  "Ualapi.dll",
  "wlanhlp.dll",
  "phoneinfo.dll",
  "EdgeGdi.dll",
  "cdpsgshims.dll",
  "windowsperformancerecordercontrol.dll",
  "diagtrack_win.dll"
  ) and
not (dll.code_signature.subject_name : ("Microsoft Windows", "Microsoft Corporation") and dll.code_signature.status : "trusted")

Framework: MITRE ATT&CKTM

• Tactic:

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

• Technique:

  • Name: Hijack Execution Flow
  • ID: T1574
  • Reference URL: https://attack.mitre.org/techniques/T1574/

• Sub-technique:

  • Name: DLL Side-Loading
  • ID: T1574.002
  • Reference URL: https://attack.mitre.org/techniques/T1574/002/

• Tactic:

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

• Technique:

  • Name: Hijack Execution Flow
  • ID: T1574
  • Reference URL: https://attack.mitre.org/techniques/T1574/

• Sub-technique:

  • Name: DLL Search Order Hijacking
  • ID: T1574.001
  • Reference URL: https://attack.mitre.org/techniques/T1574/001/