There are literally thousands of trojans, all do different things but follow the same principle of giving a person remote access to ur comp. Sub7 is a very good trojan(bad if ur a victim), it has lots of features, and allows you to do anything that ur victim can do to their comp plus more.

go to http://www.moosoft.com/ for a very good trojan scanner/remover. The default ports for sub7 are 1243 for older versions and 27374 for newer versions. I heard recently that the latest edition is 54344 or something? Anyway these are default ports, and often are changed. If ANYONE is portscanning you, they are obviously planning something nasty for you.

All they must do is type in your ip and the port, click "connect" and theyre in. Then they just click buttons and do stuff, including getting screenshots of what youre doing, keylogging you, getting ur passwords, getting ur comp info, home info (including phone, address, etc, and most maliciously, if someone gets ur ISP username/pass, they can view your credit card details as well as phone home etc ). They have full read/write access to ur harddrive, they can edit your registry etc.

So its best to get an updated VS (though these dont always pick up all trojans, eg the MooSoft trojan scanner found around 15 trojans (only 1 was running) on my comp, and my fully up to date Norton found 1, and it wasn't the running one )

If you know you have a trojan running, and MooSoft of a virus scan says it had an error while trying to delete it, or if u manually delete the file and it says "Cannot delete: the specified file is being used by windows" this means its active and waiting for a connection. Boot up in dos or open ur dos shell (MS-DOS Prompt in Start Menu>programs) and type "del c:\trojan.exe" or wherever it is located.

Alternately, if you know what trojan it is, eg netbus, sub7, progenic etc, you can get the client of this trojan (what the kiddie uses to connect and control u with) and use, if there, a delete server option. The server is the trojan, as trojans are Client>server technology.

Hope this helped.