Suspicious Lsass Process Access

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Identifies access attempts to LSASS handle, this may indicate an attempt to dump credentials from Lsass memory.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-windows.sysmon_operational-*

Severity: medium

Risk score: 47

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
  • Data Source: Sysmon

Version: 107

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
  not winlog.event_data.GrantedAccess :
                ("0x1000", "0x1400", "0x101400", "0x101000", "0x101001", "0x100000", "0x100040", "0x3200", "0x40", "0x3200") and
  not process.name : ("procexp64.exe", "procmon.exe", "procexp.exe", "Microsoft.Identity.AadConnect.Health.AadSync.Host.ex") and
  not process.executable : (
        "?:\\ProgramData\\Microsoft\\Windows Defender\\platform\\*",
        "?:\\ProgramData\\WebEx\\webex\\*",
        "?:\\Program Files (x86)\\*",
        "?:\\Program Files\\*",
        "?:\\Windows\\CCM\\CcmExec.exe",
        "?:\\Windows\\LTSvc\\LTSVC.exe",
        "?:\\Windows\\Sysmon.exe",
        "?:\\Windows\\Sysmon64.exe",
        "?:\\Windows\\system32\\csrss.exe",
        "?:\\Windows\\System32\\lsm.exe",
        "?:\\Windows\\system32\\MRT.exe",
        "?:\\Windows\\System32\\msiexec.exe",
        "?:\\Windows\\system32\\wbem\\wmiprvse.exe",
        "?:\\Windows\\system32\\wininit.exe",
        "?:\\Windows\\SystemTemp\\GUM*.tmp\\GoogleUpdate.exe",
        "?:\\Windows\\sysWOW64\\wbem\\wmiprvse.exe"
  ) and
  not winlog.event_data.CallTrace : ("*mpengine.dll*", "*appresolver.dll*", "*sysmain.dll*")

Framework: MITRE ATT&CKTM