Detection rules › Splunk

Windows Kerberos Local Successful Logon

Status
production
Severity
medium
Group by
SourcePort, action, app, authentication_method, command_line, dest, dvc, process_id, process_name, signature, signature_id, src, status, subject, user, user_group, vendor_product
Author
Michael Haag, Splunk
Source
github.com/splunk/security_content

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.

Known false positives

  • False positives are possible, particularly from domain controllers that use Kerberos SSP and loopback authentication. Add known domain controllers to the `domain_controllers` lookup to suppress those results. Filter as needed.

MITRE ATT&CK coverage

TacticTechniques
Credential Access

Telemetry coverage

Rule body

name: Windows Kerberos Local Successful Logon
id: 8309c3a8-4d34-48ae-ad66-631658214653
version: 15
creation_date: '2022-04-28'
modification_date: '2026-07-27'
author: Michael Haag, Splunk
status: production
type: TTP
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.
data_source:
    - Windows Event Log Security 4624
search: |-
    `wineventlog_security`
    EventCode=4624
    LogonType=3
    AuthenticationPackageName=Kerberos
    action=success
    src=127.0.0.1
    
    | fillnull
    | stats count min(_time) as firstTime
                  max(_time) as lastTime
      BY action app authentication_method
         dest dvc process
         process_id process_name process_path
         signature signature_id src
         src_port status subject
         user user_group vendor_product
    
    | lookup update=true domain_controllers sAMAccountName as dest OUTPUT isDC
    | where isnull(isDC)
    | fields - isDC
    
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_kerberos_local_successful_logon_filter`
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.
    Populate the `domain_controllers` lookup with the hostnames that appear in the `dest` field for domain controllers in your environment.
known_false_positives: |-
    False positives are possible, particularly from domain controllers that use Kerberos SSP and loopback authentication.
    Add known domain controllers to the `domain_controllers` lookup to suppress those results. Filter as needed.
references:
    - https://github.com/Dec0ne/KrbRelayUp
finding:
    title: A successful localhost Kerberos authentication event occurred on $dest$, possibly indicative of Kerberos relay attack.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Local Privilege Escalation With KrbRelayUp
    - Active Directory Kerberos Attacks
    - Compromised Windows Host
    - Scattered Lapsus$ Hunters
asset_type: Endpoint
mitre_attack_id:
    - T1558
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: search

`wineventlog_security`
EventCode=4624
LogonType=3
AuthenticationPackageName=Kerberos
action=success
src=127.0.0.1

Stage 2: fillnull

| fillnull

Stage 3: stats

| stats count min(_time) as firstTime
              max(_time) as lastTime
  BY action app authentication_method
     dest dvc process
     process_id process_name process_path
     signature signature_id src
     src_port status subject
     user user_group vendor_product

Stage 4: lookup

| lookup update=true domain_controllers sAMAccountName as dest OUTPUT isDC
Lookup table
domain_controllers
Key field
sAMAccountName as dest
Output columns
['isDC', 'isDC']

Stage 5: where

| where isnull(isDC)

Stage 6: fields

| fields - isDC

Stage 7: search

| `security_content_ctime(firstTime)`

Stage 8: search

| `security_content_ctime(lastTime)`

Stage 9: search

| `windows_kerberos_local_successful_logon_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
AuthenticationPackageNameeq
  • Kerberos corpus 5 (sigma 2, elastic 2, splunk 1)
field:"AuthenticationPackageName" kind:eq value:"Kerberos"
EventCodeeq
  • 4624 corpus 29 (splunk 13, kusto 11, chronicle 4, elastic 1)
field:"EventID" kind:eq value:"4624"
LogonTypeeq
  • 3 corpus 41 (splunk 13, sigma 12, elastic 9, kusto 7)
field:"LogonType" kind:eq value:"3"
actioneq
  • success corpus 3 (splunk 3)
field:"action" kind:eq value:"success"
isDCis_null
  • (no value, null check)
field:"isDC" kind:is_null
srceq
  • 127.0.0.1
field:"src" kind:eq value:"127.0.0.1"