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.
Query · spl
`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`
Implementation guide
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.
Analyst notes
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.