Attacked By A Hacker!

Urgh...A hacker hacked into my laptop yesterday evening after I had forgotten to on my firewall. The result: dangerous malware infection (whatever that is!) was detected! I had to spend the rest of that evening and the next morning - till 2 am - to search for the alien files. And I am still running the anti-spyware now concurrently just because of a crazy bastard who think it is fun to access other people's files and hard disk. I even have his IP address, though I am wondering what I can do with it...