Originally Posted by Dubdub
I think all viruses and trojans, et al, get to your PC by some sort of user disconnect. They don't get there totally by themselves.
Sometimes they do get there by themselves, with no user action. This can happen by landing on a page with an invisible iframe redirecting to a malicious site running exploits. Happens quite often actually. Not just Windows exploits, also Firefox, Adobe Reader and Acrobat, Quicktime, java, Wordpress and the list goes on and on.
The bad guys hack good normal websites and plant malicious code to spreak their evil.
Also there are worms that roam the internet waiting to infect unprotected, unpatched systems. This is from a few years ago, I don't think it happens so much now. Infected in 20 minutes • The Register
Anyone remember the slammer worm? Study: Slammer was fastest spreading worm yet | Networking - InfoWorld
I'll never forget that night when it hit, watching website after website go down. Didn't know what it was til the next morning. Very freaky.