Kerberos Traffic from Unusual Process

## Triage and analysis

### Investigating Kerberos Traffic from Unusual Process

Kerberos is the default authentication protocol in Active Directory, designed to provide strong authentication for
client/server applications by using secret-key cryptography.

Domain-joined hosts usually perform Kerberos traffic using the `lsass.exe` process. This rule detects the occurrence of
traffic on the Kerberos port (88) by processes other than `lsass.exe` to detect the unusual request and usage of
Kerberos tickets.

#### Possible investigation steps

- Investigate script execution chain (parent process tree).
- Investigate other alerts related to the host and user in the last 48 hours.
- Check if the Destination IP is related to a Domain Controller.
- Review event ID 4769 for suspicious ticket requests.

### False positive analysis

- This rule uses a Kerberos-related port but does not identify the protocol used on that port. HTTP traffic on a
non-standard port or destination IP address unrelated to Domain controllers can create false positives.
- Exceptions can be added for noisy/frequent connections.

### Response and remediation

- Initiate the incident response process based on the outcome of the triage.
- Scope possible compromised credentials based on ticket requests.
- Isolate the involved host to prevent further post-compromise behavior.

## Config

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.