I got a buncha angry replies in my inbox Thursday because I'd apparently sent out a massive spam email to everyone in my (admittedly unkempt) inbox. I don't think I got phished using phony sites, so I've apparently picked up some sort of bot. I've since changed the password to my email account, but obviously, if they've gotten my password once, they can get it again. I'm using an anti-virus software, and consider myself to be "moderately web savy" in terms of what I download, what sites I visit, etc. What's the best way to deal with this, determine the nature of attack, and prevent it from occurring again?