Having used Apple Macs for over 16 years, today was the first time I have ever seen a Mac infected with malware!
The virus which infected the customer's iMac was a program called MACSecurity (MACDefender and MACProtector are some other names it maybe called) which would run once the desktop had loaded and then look like it was scanning your Mac for virus's (even displaying names of real virus's) and finding them, then asking you to registar and pay $20-$30 to fix the alleged problems it found.
It probably works in the same way the Windows malware/spyware works, where they will take your money, maybe a lot more than the $20-$30 they say it will cost, but the program will not remove anything.
So if you have something come up like that on your Mac then don't click on 'register', give PC PAL a call instead. Find an engineer near you!
