CyberHunter
Local dataset, no network
// Other services

Port 3261: winShadow

Port 3261 is assigned by IANA to winshadow (winShadow).

3261

How winshadow works

Other services
client:3261winshadowresponse client:3261winshadowresponse

The client sends a request to port 3261 and the winshadow service answers.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned1 registered service
Range
Registered (1024-49151)
01 Security

Is port 3261 dangerous?

We have no specific security note for port 3261. Its risk depends on the program actually listening on it. General advice for other services services:

  • Close the port if nothing on the host needs it.
  • Identify the process that listens on it (commands below) before opening it in a firewall.
  • Expose a service only to the networks that use it.
02 Registry

IANA registry entries for port 3261

ServicePortTransportDescriptionReferenceUpdated
winshadow 3261 TCP, UDP winShadow - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 3261, and is it reachable?

Linux

sudo ss -ltnup 'sport = :3261'      # process listening on 3261
sudo lsof -nP -i :3261

macOS

sudo lsof -nP -i :3261

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3261 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 3261
netstat -ano | findstr :3261

From another machine

nmap -p 3261 -sV <host>
sudo nmap -sU -p 3261 <host>
nc -zv <host> 3261

Block it in the firewall

sudo ufw deny 3261/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 3261" -Direction Inbound -LocalPort 3261 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 3261 used for?

Port 3261 is assigned by IANA to winshadow (winShadow).

Is port 3261 TCP or UDP?

Port 3261 is registered for TCP and UDP.

Is it safe to open port 3261?

It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Close the port if nothing on the host needs it.

How do I check if port 3261 is open?

On Linux run "ss -ltnup 'sport = :3261'", on macOS "lsof -nP -i :3261", and on Windows "netstat -ano | findstr :3261" to see the local process. From another machine, "nmap -p 3261 <host>" shows whether it is reachable.

05 Related

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