Either temporarily stop the service associated with it, or put up a firewall and config it to only block certain ip's that you don't want. Also, it could just be you connecting to a website, in that case just close your browser. You could also pull your network plug. But yeah, if I feel that something bad is happening when I look at netstat, I generally stop the service and block at the firewall. I have a hardware firewall, so I just go into the web config and set it to close that virtual server pointing to whatever service. That should do you just fine. There is also probably a program that allows you to monitor who is connected to your computer and kill there connection, try a google search. If there is no program like that, there darn well should be, and I would like to have it. Good luck.