Computer viruses suck.
They delete files, corrupt kernels and generally make life on your computer a living hell until they're fixed. Luckily, YOU have probably never had one.
Viruses aren't exactly common place anymore, and that "virus alert" you get from your anti-virus software is more likely than not for a trojan, a piece of adware, or a piece of spyware installed by a plugin when you were trying to download free movie samples from "jigglytrunkjunk.com"
So who writes these things? Who creates the viruses that destroy your life and hamper your porn surfage? Dunno, but they're not usually geeks.
However we can tell you exactly HOW you got the "virus".
Jesus Pop-and-Locking Christ.
Everyone thinks that they can google the word torrent, throw on an eye patch and impress their friends with a bootleg of Shrek 3 without Comcast finding out and sending a letter to you that your friends now openly mock you for. Just because you have a racecar doesnt mean that youve magically gained the ability to drive it, and dont come crying to us when you end up an Earnhardtian smear on the wall because we will have zero sympathy.
Learn all you need to know at It's All Geek to Me.