> 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/kerberos-pre-auth-failures-by-host.md).

# Kerberos Pre-Auth Failures by Host

### Synopsis

| Field                | Value                                                                                                       |
| -------------------- | ----------------------------------------------------------------------------------------------------------- |
| Activation Period    | 14 Days                                                                                                     |
| Training Period      | 30 Days                                                                                                     |
| Test Period          | 10 Minutes                                                                                                  |
| Deduplication Period | 1 Hour                                                                                                      |
| Required Data        | <p>Requires one of the following data sources:<br>Palo Alto Networks Firewall traffic Logs OR XDR Agent</p> |
| ATT\&CK Tactic       | Credential Access (TA0006)                                                                                  |
| ATT\&CK Technique    | Brute Force (T1110)                                                                                         |
| Severity             | Low                                                                                                         |

### Description

The endpoint failed an unusual number of Kerberos pre-authentications (TGT requests) from at least three users when compared to its baseline. This can 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

* Verify whether the host that generated the alert is normally used by many users (for example, a terminal server).
* Verify any later authentication success for the user accounts referenced by the alert, as these can indicate the attacker managed to guess the credentials.


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