# outbound\_tcp\_4444 **Explanation** The outbound\_tcp\_4444 NDM flags connections leaving the customer network to hosts listening on TCP port 4444. Metasploit uses port 4444 by default for shell listeners that are setup after exploitation, so the use of this port could indicate successful exploitation of a remote code execution vulnerability in a running service on the source host. **What to Look For** Exploitation activity leaving your network could be an indication that your network is compromised. Investigate the traffic to determine if it is benign and authorized or if it looks suspicious. If so, investigate the host connecting to port 4444 (the destination IP in this case) to determine if it has been compromised. **Related MITRE ATT\&CK Categories** [Initial Access: Exploit Public-Facing Application, Technique T1190 - Enterprise](https://attack.mitre.org/techniques/T1190) --- # Agent Instructions: 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: ``` GET https://docs.fusion.vectra.ai/detection-models/library/attack/outbound_tcp_4444.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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.