Interactive Logon by an Unusual Process

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Identifies interactive logon attempt with alternate credentials and by an unusual process. Adversaries may create a new token to escalate privileges and bypass access controls.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-system.*
  • logs-windows.*

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: Privilege Escalation

Version: 2

Rule authors:

  • Elastic

Rule license: Elastic License v2

Setup

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Audit event 4624 is needed to trigger this rule.

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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authentication where
 host.os.type : "windows" and winlog.event_data.LogonProcessName : "Advapi*" and
 winlog.logon.type == "Interactive" and winlog.event_data.SubjectUserSid : ("S-1-5-21*", "S-1-12-*") and
 winlog.event_data.TargetUserSid : ("S-1-5-21*", "S-1-12-*")  and process.executable : "C:\\*" and
 not startswith~(winlog.event_data.SubjectUserSid, winlog.event_data.TargetUserSid) and
 not process.executable :
            ("?:\\Windows\\System32\\winlogon.exe",
             "?:\\Windows\\System32\\wininit.exe",
             "?:\\Program Files\\*.exe",
             "?:\\Program Files (x86)\\*.exe",
             "?:\\Windows\\SysWOW64\\inetsrv\\w3wp.exe",
             "?:\\Windows\\System32\\inetsrv\\w3wp.exe",
             "?:\\Windows\\SysWOW64\\msiexec.exe")

Framework: MITRE ATT&CKTM