Lmarc wrote:
Maybe things have changed, but I always thought a virus had to be activated in some way, such as clicking on a link in an email or on a website, or downloading an infected ".exe" file or a zip file containing an ".exe" file.
Not so much anymore. There are so many kinds of files now that can 'embed' themselves in your OS somewhere without you even knowing it. The number of ways an infected file can get in to your system is almost endless. Background transfers, infected image files, rogue "spyware alert" software that infects your computer with a trojan when you click "Get a Free Scan NOW!", the list goes on and on. The best one can do is keep the spyware and virus software up to date, and learn how not to do stupid stuff.
For the uninitiated, there is NO WAY an "anti-spyware" program can know your system has "326 trojans, spyware and viruses" in the 5 seconds it takes to load that bogus web page. Nearly ALL of those programs are false-front spyware delivery vehicles that will infect your computer before you can say diddly squat. DO NOT fall for the "Free PC Scan".