> 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/misconfiguration/registered_ports_ext_int.md).

# registered\_ports\_ext\_int

**Explanation**

The registered\_ports\_ext\_int NDM looks for any traffic accepted onto your network from the Internet on IANA registered ports. These ports are less commonly exposed to the Internet than well-known ports and might represent a misconfiguration, untracked servers, or malicious activity.

**What to Look For**

It's a good idea to tune this NDM to exempt IPs and ports that you expect to be accessible from the Internet, and then to investigate all other events. Some malware may open ports for a short amount of time, so it's recommended to investigate events even if they are not currently active. Check your network and endpoint logs for any suspicious activity related to the identified ports and take appropriate remediation steps to mitigate any security risks.

**Related MITRE ATT\&CK Categories**

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

[Command and Control, Defense Evasion, Persistence: Traffic Signaling, Technique T1205 - Enterprise](https://attack.mitre.org/techniques/T1205)


---

# 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/misconfiguration/registered_ports_ext_int.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.