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Description

The following analytic identifies a local successful authentication event on a Windows endpoint using the Kerberos package. It detects EventCode 4624 with LogonType 3 and source address 127.0.0.1, indicating a login to the built-in local Administrator account. This activity is significant as it may suggest a Kerberos relay attack, a method attackers use to escalate privileges. If confirmed malicious, this could allow an attacker to gain unauthorized access to sensitive systems, execute arbitrary code, or create new accounts in Active Directory, leading to potential system compromise.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Authentication
  • Last Updated: 2024-05-14
  • Author: Michael Haag, Splunk
  • ID: 8309c3a8-4d34-48ae-ad66-631658214653

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1558 Steal or Forge Kerberos Tickets Credential Access
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


1
2
3
4
5



`wineventlog_security`  EventCode=4624 LogonType=3 AuthenticationPackageName=Kerberos action=success src=127.0.0.1 
| stats count min(_time) as firstTime max(_time) as lastTime by dest, subject, action, SubjectLogonId, user, TargetUserName, src 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_kerberos_local_successful_logon_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_kerberos_local_successful_logon_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • dest
  • subject
  • action
  • Security_ID
  • user
  • TargetUserName
  • src_ip

How To Implement

To successfully implement this search, you need to be ingesting Windows Security Event Logs with 4624 EventCode enabled. The Windows TA is also required.

Known False Positives

False positives are possible, filtering may be required to restrict to workstations vs domain controllers. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
64.0 80 80 A successful localhost Kerberos authentication event occurred on $dest$, possibly indicative of Kerberos relay attack.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 3