Detection rules › Splunk

Windows Large Number of Computer Service Tickets Requested

Status
production
Severity
low
Group by
_time, src_ip, user
Author
Mauricio Velazco, Splunk
Source
github.com/splunk/security_content

The following analytic detects a high volume of Kerberos service ticket requests, specifically more than 30, from a single source within a 5-minute window. It leverages Event ID 4769, which logs when a Kerberos service ticket is requested, focusing on requests with computer names as the Service Name. This behavior is significant as it may indicate malicious activities such as lateral movement, malware staging, or reconnaissance. If confirmed malicious, an attacker could gain unauthorized access to multiple endpoints, potentially compromising the entire network.

Known false positives

  • An single endpoint requesting a large number of kerberos service tickets is not common behavior. Possible false positive scenarios include but are not limited to vulnerability scanners, administration systems and missconfigured systems.

MITRE ATT&CK coverage

TacticTechniques
Initial Access
Persistence
Privilege Escalation
Stealth
Discovery

Telemetry coverage

Rule body

name: Windows Large Number of Computer Service Tickets Requested
id: 386ad394-c9a7-4b4f-b66f-586252de20f0
version: 12
creation_date: '2023-03-21'
modification_date: '2026-07-05'
author: Mauricio Velazco, Splunk
status: production
type: Anomaly
description: |-
    The following analytic detects a high volume of Kerberos service ticket requests, specifically more than 30, from a single source within a 5-minute window.
    It leverages Event ID 4769, which logs when a Kerberos service ticket is requested, focusing on requests with computer names as the Service Name. This behavior is significant as it may indicate malicious activities such as lateral movement, malware staging, or reconnaissance.
    If confirmed malicious, an attacker could gain unauthorized access to multiple endpoints, potentially compromising the entire network.
data_source:
    - Windows Event Log Security 4769
search: |-
    `wineventlog_security` EventCode=4769 ServiceName="*$" TargetUserName!="*$"
    | eval TargetUserName = mvindex(split(TargetUserName, "@"), 0)
    | search NOT TargetUserName="*$"
    | bucket span=5m _time
    | stats dc(ServiceName) AS unique_targets
            values(ServiceName) as host_targets
            values(dest) as dest
      by _time, IpAddress, TargetUserName
    | where unique_targets > 30
    | `windows_large_number_of_computer_service_tickets_requested_filter`
how_to_implement: To successfully implement this search, you need to be ingesting Domain Controller and Kerberos events. The Advanced Security Audit policy setting `Audit Kerberos Authentication Service` within `Account Logon` needs to be enabled.
known_false_positives: An single endpoint requesting a large number of kerberos service tickets is not common behavior. Possible false positive scenarios include but are not limited to vulnerability scanners, administration systems and missconfigured systems.
references:
    - https://thedfirreport.com/2023/01/23/sharefinder-how-threat-actors-discover-file-shares/
    - https://attack.mitre.org/techniques/T1135/
    - https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4769
intermediate_findings:
    entities:
        - field: IpAddress
          type: system
          score: 20
          message: A large number of kerberos computer service tickets were requested by $IpAddress$ within 5 minutes.
analytic_story:
    - Active Directory Privilege Escalation
    - Active Directory Lateral Movement
asset_type: Endpoint
mitre_attack_id:
    - T1135
    - T1078
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: search

`wineventlog_security` EventCode=4769 ServiceName="*$" TargetUserName!="*$"

Stage 2: eval

| eval TargetUserName = mvindex(split(TargetUserName, "@"), 0)

Stage 3: search

| search NOT TargetUserName="*$"

Stage 4: bucket

| bucket span=5m _time

Stage 5: stats

| stats dc(ServiceName) AS unique_targets
        values(ServiceName) as host_targets
        values(dest) as dest
  by _time, IpAddress, TargetUserName

Stage 6: where

| where unique_targets > 30

Stage 7: search

| `windows_large_number_of_computer_service_tickets_requested_filter`

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
TargetUserNameeq"*$"excludes:TargetUserName

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventCodeeq
  • 4769 corpus 11 (splunk 6, kusto 4, elastic 1)
field:"EventID" kind:eq value:"4769"
ServiceNameeq
  • "*$" corpus 4 (sigma 2, splunk 2)
field:"ServiceName" kind:eq
TargetUserNamene
  • "*$" corpus 14 (splunk 14)
field:"TargetUserName" kind:ne
unique_targetsgt
  • 30 corpus 5 (splunk 5)
field:"unique_targets" kind:gt value:"30"