Potential Credential Access via LSASS Memory Dump

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.sysmon_operational-*

Severity: high

Risk score: 73

Runs every: 5m

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

Maximum alerts per execution: 100

References:

Tags:

Domain: Endpoint
OS: Windows
Use Case: Threat Detection
Tactic: Credential Access
Tactic:Execution
Data Source: Sysmon

Version: 310

Rule authors:

Elastic

Rule license: Elastic License v2

Setup

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Setup

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 version 8.2. Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate event.ingested to @timestamp. For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html

Rule query

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process where host.os.type == "windows" and 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\\SysWOW64\\WerFault.exe",
        "?:\\Windows\\System32\\WerFaultSecure.exe"
      )

Framework: MITRE ATT&CK^TM

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/
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
Technique:
- Name: Native API
- ID: T1106
- Reference URL: https://attack.mitre.org/techniques/T1106/

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