View Full Version : open ports

23-11-2001, 06:35 PM
I tried one of the security checks which can sometimes be found on the internet,wherein they run a check on how secure your computor is. The respnse was that my computor was exceedingly secure except for the fact that ports 135 & 139 were open.
Is this grevious ? & if so how can I fix it.
Thanks in anticipation

23-11-2001, 07:26 PM
Port 139 is default port for netbios, I assume you r running windows as these posrts are left open by default.

It is possible to be hacked on these open ports but its rare. However stay tuned as someone will know more.

But you could checkout grc.com as im sure I read something there on this problem and how to close the ports.

23-11-2001, 07:44 PM
Port 139 is used by NetBIOS. Trojans such as Chode, God Message worm, Msinit, Netlog, Network, and Qaz may also access this port which is a good reason to make sure it is closed. If you do not need the NetBIOS protocol then you should uninstall it (only TCP/IP is needed for internet connection). Do this through the Network applet in the control panel.

For more information on blocking port 139 go to http://grc.com/faq-shieldsup.htm#139

You can also block this port by installing a firewall such as Zonealarm (http://www.zonelabs.com/)

For more information on port blocking check out Shields Up! at http://grc.com

29-11-2001, 10:18 PM
Hi Bob

Just wanted to add an endorsement to Tristan's comments about ZoneAlarm.

I downloaded my copy from


and have loved every inch of it.

It is Freeware for personal use and as it keeps track of apps dialing OUT from your computer as well as in, I have used it with great success to track viruses and other suspect programs on machines with no controls.

ZoneAlarm is a Firewall that you can configure painlessly, and I definitely recommend you check it out, whether or not you are concerned about your PC security ... you'll be surprised at how much traffic you REALLY handle.