Port Authority Edition – Internet Vulnerability Profiling
by Steve Gibson,  Gibson Research Corporation.





Goto Port 138
Probe Port 139
Enter Port: 0-65535
Goto Port 140



Port Authority Database

Port 139

Name: 
netbios-ssn

Purpose: 
NETBIOS Session Service

Description: 
TCP NetBIOS connections are made over this port, usually with Windows machines but also with any other system running Samba (SMB). These TCP connections form "NetBIOS sessions" to support connection oriented file sharing activities.

Related Ports: 
137, 138, 445




Background and Additional Information:

This is the third port of the original "NetBIOS trio" used by the first Windows operating systems (up through Windows NT) in support of file sharing.

For additional information about this trio of Internet ports, please see the "Background and Additional Information" for the first port of the trio, port 137.

Trojan Sightings: Chode, God Message worm, Msinit, Netlog, Network, Qaz, Sadmind, SMB Relay

The entire contents of this page is copyright © 2008 by Gibson Research Corporation.


Jump to top of page
Gibson Research Corporation is owned and operated by Steve Gibson.  The contents
of this page are Copyright (c) 2016 Gibson Research Corporation. SpinRite, ShieldsUP,
NanoProbe, and any other indicated trademarks are registered trademarks of Gibson
Research Corporation, Laguna Hills, CA, USA. GRC's web and customer privacy policy.
Jump to top of page