Potential Credential Access via LSASS Memory Dump

Elastic Stack Serverless Security

Identifies suspicious access to LSASS handle from a call trace pointing to DBGHelp.dll or DBGCore.dll, which both export the MiniDumpWriteDump method that can be used to dump LSASS memory content in preparation for credential access.

Rule type: eql

Rule indices:

• winlogbeat-*
• 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://www.ired.team/offensive-security/credential-access-and-credential-dumping/dump-credentials-from-lsass-process-without-mimikatz

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Credential Access

Version: 6

Rule authors:

• Elastic

Rule license: Elastic License v2

process where event.code == "10" and
  winlog.event_data.TargetImage : "?:\\WINDOWS\\system32\\lsass.exe" and

   /* DLLs exporting MiniDumpWriteDump API to create an lsass mdmp*/
  winlog.event_data.CallTrace : ("*dbghelp*", "*dbgcore*") and

   /* case of lsass crashing */
  not process.executable : ("?:\\Windows\\System32\\WerFault.exe", "?:\\Windows\\System32\\WerFaultSecure.exe")

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Credential Access
  • ID: TA0006
  • Reference URL: https://attack.mitre.org/tactics/TA0006/

• Technique:

  • Name: OS Credential Dumping
  • ID: T1003
  • Reference URL: https://attack.mitre.org/techniques/T1003/

• Sub-technique:

  • Name: LSASS Memory
  • ID: T1003.001
  • Reference URL: https://attack.mitre.org/techniques/T1003/001/