The last three
The last three times my antivirus program gave an alert and stopped a virus or trojan..... was when I downloaded a CRACK to some program I liked and didn't want to pay for. My guess is that many people that get infected get them through crack sites, you gotta be real carefull where you click there, and without an updated anti virus program, people with not much experience but have heard something about "serialz" and "crackz" will be easy, easy targets.
The problem of many people? Their free subscription for a year they got with their PC has ran out, and they don't want to pay for renewal. They don't know how to uninstall the software properly and re-install a free antivirus program.
Viruses get released every day. Updates for antivirus at least once a week, often multple times a week. But if you stop getting your updates because your subscription ran out and you are too cheap to pay for it OR you don't replace it with a good free antivirus, you will be asking for trouble sooner or later.
"Any society that would give up a little liberty to gain a little security will deserve neither and lose both" -
Benjamin Franklin, Founding Father.
A good point - Most consumer PCs I run across have expired pre-installed AV on them. Ran across just that today, doing a favor cleaning up malware on a laptop for a friend who let guests browse on it.
My guess is that they were the "1,000,000th visitor" or "Won a free ipod/iphone" etc.
Once I uninstalled Norton and all its bloat accessories, the boot memory footprint of the machine dropped by over half. Loaded up AVG. After detecting another trojan that Clamwin had missed, they now have a much faster machine.
There are so many terms for it.. PBKAC, ID-10-T.. Seat Box failure is my favorite...