Port 2567: Unassigned — Registered but Unclaimed

Port 2567 belongs to the registered port range (1024–49151) and has no service assigned by IANA.¹ That means no protocol owns this address, no RFC defines what should run here, and nothing is supposed to be listening on it by default.

What the Registered Range Means

The Internet's port numbers are divided into three tiers:²

• Well-known ports (0–1023): Reserved for core Internet services — HTTP, DNS, SSH, SMTP. Requires IANA assignment and typically system privileges to use.
• Registered ports (1024–49151): Available for assignment to specific applications and protocols. Any party can apply to register a port number with IANA following the process defined in RFC 6335.³
• Dynamic/ephemeral ports (49152–65535): Temporarily assigned by the operating system for outbound connections. Never registered.

Port 2567 is in the second tier. It's a valid, reachable port number that any application can bind to. It's just that no application has officially registered it.

Security Scanners and This Port

Some port scanning databases and security tools have historically flagged port 2567 as a potential indicator of malicious activity.⁴ This isn't specific to a named, well-documented trojan — it reflects a general pattern: malware tends to occupy unassigned ports precisely because nothing legitimate is supposed to be there. If a firewall sees traffic on port 2567 and has no record of why, that's a reasonable signal to investigate.

An open port 2567 on a system you control isn't automatically a problem. It means something chose this port. The question is whether you know what that something is.

How to Check What's Listening

Linux/macOS:

# Show what process is bound to port 2567
sudo ss -tlnp | grep 2567

# Or with lsof
sudo lsof -i :2567

Windows:

netstat -ano | findstr :2567

The process ID in the output will tell you what application claimed the port. Cross-reference against tasklist (Windows) or ps aux (Linux/macOS).

Why Unassigned Ports Matter

The registered range has 48,128 port numbers. Only a fraction are assigned. The rest sit empty — not blocked, not forbidden, just unclaimed. Applications can and do use them without registering, which is why you'll occasionally find software running on a port with no official paper trail.

If you see port 2567 open on a server you manage and you didn't put it there, find out what did.