Detection rules › Splunk
Windows Multiple Disabled Users Failed To Authenticate Wth Kerberos
The following analytic detects a single source endpoint failing to authenticate with 30 unique disabled domain users using the Kerberos protocol within 5 minutes. It leverages Windows Security Event 4768, focusing on failure code 0x12, indicating revoked credentials. This activity is significant as it may indicate a Password Spraying attack targeting disabled accounts, a tactic used by adversaries to gain initial access or elevate privileges. If confirmed malicious, this could lead to unauthorized access or privilege escalation within the Active Directory environment, posing a severe security risk.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Credential Access | T1110.003 Brute Force: Password Spraying |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4768 | A Kerberos authentication ticket (TGT) was requested. |
Rule body splunk
name: Windows Multiple Disabled Users Failed To Authenticate Wth Kerberos
id: 98f22d82-9d62-11eb-9fcf-acde48001122
version: 12
creation_date: '2021-04-14'
modification_date: '2026-05-13'
author: Mauricio Velazco, Splunk
status: production
type: TTP
description: The following analytic detects a single source endpoint failing to authenticate with 30 unique disabled domain users using the Kerberos protocol within 5 minutes. It leverages Windows Security Event 4768, focusing on failure code `0x12`, indicating revoked credentials. This activity is significant as it may indicate a Password Spraying attack targeting disabled accounts, a tactic used by adversaries to gain initial access or elevate privileges. If confirmed malicious, this could lead to unauthorized access or privilege escalation within the Active Directory environment, posing a severe security risk.
data_source:
- Windows Event Log Security 4768
search: |-
`wineventlog_security` EventCode=4768 TargetUserName!=*$ Status=0x12
| bucket span=5m _time
| stats dc(TargetUserName) AS unique_accounts values(TargetUserName) as user values(dest) as dest
BY _time, IpAddress
| where unique_accounts > 30
| `windows_multiple_disabled_users_failed_to_authenticate_wth_kerberos_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: A host failing to authenticate with multiple disabled domain users is not a common behavior for legitimate systems. Possible false positive scenarios include but are not limited to vulnerability scanners, multi-user systems missconfigured systems.
references:
- https://attack.mitre.org/techniques/T1110/003/
drilldown_searches:
- name: View the detection results for - "$user$"
search: '%original_detection_search% | search user = "$user$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$user$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset: 7d
latest_offset: "0"
finding:
title: Potential Kerberos based password spraying attack from $IpAddress$
entity:
field: user
type: user
score: 50
threat_objects:
- field: IpAddress
type: ip_address
analytic_story:
- Active Directory Password Spraying
- Active Directory Kerberos Attacks
- Volt Typhoon
asset_type: Endpoint
mitre_attack_id:
- T1110.003
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
- attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1110.003/purplesharp_disabled_users_kerberos_xml/windows-security.log
source: XmlWinEventLog:Security
sourcetype: XmlWinEventLog
name: True Positive Test
test_type: unit
Stages and Predicates
Stage 1: search
`wineventlog_security` EventCode=4768 TargetUserName!=*$ Status=0x12
Stage 2: bucket
| bucket span=5m _time
Stage 3: stats
| stats dc(TargetUserName) AS unique_accounts values(TargetUserName) as user values(dest) as dest
BY _time, IpAddress
Stage 4: where
| where unique_accounts > 30
Stage 5: search
| `windows_multiple_disabled_users_failed_to_authenticate_wth_kerberos_filter`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
Status | eq |
|
TargetUserName | ne |
|
unique_accounts | gt |
|