Some of the virus,spyware,adware and firewall software may have tracking in it(maybe check log) and the ablity to report to your software vender's web site.You will have to check your documentation or help files.Your service provider(tech support) would also like to know.After all it is going through thier server and may or could be affecting them as well other customers( they may track it for themselves,after all they are the professionals and also may offer some helpful tools from thier site). They can help sometimes.

To prevent future attack or lessen attacks...

A router is a good to have. I connect my adsl modem to it and my computer to the router. It acts as a physical firewall which can let you hide your ip address(not 100% but better than nothing) and allow you to turn some ports off.

I got so tired of the viruses and other crap that at one time I was running three types of scanning software(this can cause problems when trying to surf the net or run offline software). With eveyone of one them running,I could scan and find some type of virus,spyware or some other nasty stuff.One software would would pick some of it up but then other would find more but not what the other software found.

Find the best protection software for your computer.

I use Zone Alarm now. I have also used Spy Sweeper and AdAware SE.
Be aware of porn sites.. just like in real life these are loaded with viruses.. all kinds of s**t . Wares sites are maybe the worst. Many of them are run by hackers.. or hacker want ta bes.
the word," FREE" as in free softeware is good bait which can hide a trojan. If you must download,at least scan it before opening.

These are a few things I learn in the school of hard knocks.

please correct me if there are any errors...