your isp gave your clearance to hack in defense? That's sorta messed up.
Netstat -n is good, but you don't really know which one is them, the command "netstat" without any flags, will give you a look at the hostname of everyone who you are connected to.
But, how do you know they are hackers? What are they doing to your computer?
You might want to pick up a firewall, like
Sygate Personal Firewall Pro to be completely sure someone is messing with your pc, and it's not just a technical difficulty in your system.
Sygate will also give you the IP address of the person who is tryign to attack you, so you could easily do a whois on the ip address at a site like
http://whois.userland.com, find out who the ISP is, and then email the abuse department of the ISP.
This would be hell of alot better than trying to reverse an attack from someone. That could actually land you in prison.
BTW... Who is your ISP?