> For the complete documentation index, see [llms.txt](https://docs.fusion.vectra.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fusion.vectra.ai/detection-models/library/post-compromise/cups_browsed_internal_external.md).

# cups\_browsed\_internal\_external

**Explanation**

This event is triggered by Netography's Fusion Portal when it detects traffic on UDP port 631 exiting your network. UDP port 631 is usually associated with the CUPS-Browsed service and is used to automatically add available local printers. While it may be odd by itself, this traffic may also indicate a compromise and that an attacker is attempting to trigger CVE-2024-47176 on other hosts from your network.

**What to Look For**

Investigate the source of these requests for malware infection or unauthorized software, and consider blocking UDP port 631 at the firewall.

**Related MITRE ATT\&CK Categories**

[Initial Access, Persistence: External Remote Services, Technique T1133 - Enterprise](https://attack.mitre.org/techniques/T1133)

[Initial Access: Exploit Public-Facing Application, Technique T1190 - Enterprise](https://attack.mitre.org/techniques/T1190)


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.fusion.vectra.ai/detection-models/library/post-compromise/cups_browsed_internal_external.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.