> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/analytics-alerts/alerts-by-name/suspicious-kerberos-pre-auth-failures-by-host.md).

# Suspicious Kerberos Pre-Auth Failures by Host

### Synopsis

| Field                | Value                                        |
| -------------------- | -------------------------------------------- |
| Activation Period    | 14 Days                                      |
| Training Period      | 30 Days                                      |
| Test Period          | 10 Minutes                                   |
| Deduplication Period | 1 Day                                        |
| Required Data        | XDR Agent with eXtended Threat Hunting (XTH) |
| Detection Modules    | Identity Analytics                           |
| ATT\&CK Tactic       | Credential Access (TA0006)                   |
| ATT\&CK Technique    | Brute Force: Password Spraying (T1110.003)   |
| Severity             | Low                                          |

### Description

An endpoint failed unusual number of Kerberos pre-authentications (TGT requests) which may indicate a password-spraying attack.

### Attacker's Goals

The attacker is attempting to gain an initial foothold in the domain using a list of valid users and a guessed password.

### Investigative actions

* Identify the source host from which the failed logons originated, by making sure the IP is not a shared address.
* Review source host activity to detect any additional suspicious or lateral movement behavior.
* Correlate successful logons from the source host to identify potential account compromises following the failed attempts.


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