Port 4421ScaleFT

TCP 4421 is assigned to ScaleFT's multi-platform remote-management service for cloud infrastructure.

transport: tcp
in transit: encrypted
assignment: official
risk: 1/10
lookups: 0

Technical Details

what runs on :4421

ScaleFT is registered on port :4421 over tcp to ScaleFT Inc, assigned April 2016. We don't have a technical write-up for it beyond the IANA registry entry.

In nmap's internet-wide scan data this port is never observed open, so if it's open on your network it's more likely a custom or misconfigured service than the registered one.

find what's listening on :4421

this machine

# linux
sudo ss -tlpn 'sport = :4421'

# macos / bsd
sudo lsof -nP -i :4421

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :4421

another host

nmap -sV -p T:4421 <host>

run it? the handshake, the implementations you meet in the wild and the flags that matter come from the engineers who do.

add technical details

Security Information

exposure of :4421

risk score

1/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

remote access averages 3.8 across 205 ports — this one sits 2.8 below.

in transit

encrypted

payloads are protected on the wire

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp

every listening transport is another surface to filter at the edge

security overview

no security notes recorded for :4421 yet

known exploits, hardening advice, what a compromise looks like — suggest an edit if you know its exposure.

Record

iana registry entry

port: :4421
service: ScaleFT
transport: TCP
encryption: tls / encrypted
assignment: iana registered
risk: 1/10safe
category: Remote Access Cloud
usage: The assignment identifies ScaleFT's cloud-infrastructure remote-management service, registered to ScaleFT Inc. The port has not been observed open in the cited internet-wide scan data, and there is not enough established port-specific information to describe a typical listener.
lookups: 0rank 993
added: 2026-10-04
updated: 2026-10-04
references: IANA service name registry — port 4421

Something wrong?

This record is maintained by the engineers who use port 4421. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-10-04.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

all 205 in remote access →

the 8 most looked-up other ports in remote access — 205 ports carry that label.

port	service	proto	category	risk	views
:8000	Intel Remote Desktop / Alternate HTTP Port	TCP	Web Services	safe	84.3k
:8888	D2GS Admin Console	TCP	Remote Access	caution	83.7k
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
:5938	TeamViewer	TCPUDP	Remote Access	caution	65.0k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:8008	IBM HTTP Server Admin	TCP	Web Services	caution	58.3k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:23	Telnet	TCP	Remote Access	caution	34.8k

risk mix of the 8 listed

safe13%
caution88%

0 of 8 encrypted

Port :4421ScaleFT

Technical Details

Security Information

Related Ports

Port 4421ScaleFT