ID | Technique | Tactic |
---|---|---|
T1110.003 | Password Spraying | Credential Access |
T1110 | Brute Force | Credential Access |
Detection: Windows Multiple Disabled Users Failed To Authenticate Wth Kerberos
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.
Search
1`wineventlog_security` EventCode=4768 TargetUserName!=*$ Status=0x12
2| bucket span=5m _time
3| stats dc(TargetUserName) AS unique_accounts values(TargetUserName) as user by _time, IpAddress
4| where unique_accounts > 30
5| `windows_multiple_disabled_users_failed_to_authenticate_wth_kerberos_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Windows Event Log Security 4768 | Windows | 'xmlwineventlog' |
'XmlWinEventLog:Security' |
N/A |
Macros Used
Name | Value |
---|---|
wineventlog_security | eventtype=wineventlog_security OR Channel=security OR source=XmlWinEventLog:Security |
windows_multiple_disabled_users_failed_to_authenticate_wth_kerberos_filter | search * |
windows_multiple_disabled_users_failed_to_authenticate_wth_kerberos_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Notable | Yes |
Rule Title | %name% |
Rule Description | %description% |
Notable Event Fields | user, dest |
Creates Risk Event | True |
Implementation
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.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Potential Kerberos based password spraying attack from $IpAddress$ | 49 | 70 | 70 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | XmlWinEventLog:Security |
xmlwineventlog |
Integration | ✅ Passing | Dataset | XmlWinEventLog:Security |
xmlwineventlog |
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: GitHub | Version: 3