Port 3417: ConServR — Registered, Forgotten, Flagged

What Range This Port Belongs To

Port 3417 sits in the registered port range (1024-49151). This range is where applications, services, and vendors can formally claim a port number by registering it with the Internet Assigned Numbers Authority (IANA). Unlike well-known ports (0-1023), registered ports don't require elevated privileges to open, and the registrations are often voluntary — meaning the IANA database is full of services that were registered, used briefly, or never deployed at all.

Registration means someone filed the paperwork. It doesn't mean anyone is home.

The Official Tenant: ConServR

IANA assigned port 3417 (TCP and UDP) to ConServR, a file translation service, in February 2002.¹ The service name in the registry is abbreviated as csvr.

ConServR is effectively a ghost. There's no RFC defining the protocol, no documentation of its architecture, no open-source implementations, and no notable deployments in the wild. Whatever problem it was meant to solve, it didn't survive long enough to leave a record.

This is more common than you'd expect. The registered port range contains hundreds of services registered during the early 2000s that were never widely adopted or have since been discontinued. The IANA registry captures intention, not usage.

The More Notable Association: Xposure

Port 3417 appears in security databases as a port used by the Xposure trojan — a remote access trojan (RAT) that targeted Windows systems.² RATs use fixed port numbers to establish command-and-control channels, and Xposure chose 3417.

Xposure is old-era malware, largely dormant today. But its association with this port means legacy firewall rules and intrusion detection signatures still flag activity here. If a security scanner warns you about port 3417, this is why.

The trojan arguably got more use out of this port than ConServR ever did.

How to Check What's Listening

If you see port 3417 active on a machine, here's how to investigate:

On Linux/macOS:

# Show process listening on port 3417
ss -tlnp | grep 3417

# Or with lsof
lsof -i :3417

On Windows:

# Show process and PID
netstat -ano | findstr :3417

# Look up the PID
tasklist | findstr <PID>

The process name will tell you whether this is legitimate software you recognize or something worth investigating further.

Why Unassigned and Ghost Ports Matter

Port 3417 illustrates something important about how the port system actually works: the map and the territory diverge.

The IANA registry is authoritative but not exhaustive. It captures what was registered, not what's running. Ports get claimed and abandoned. Malware picks squatters' rights in quiet corners. Dynamic ephemeral ports overlap the registered range on busy systems.

This is why security-minded network operators don't filter by "registered vs. unregistered" — they filter by what's expected. Anything listening on a port that isn't explicitly accounted for in your network baseline is worth a second look, regardless of what IANA says about it.