I have to be very amused when viruses and malware on Macs are described as something new.
The fact is that in the old days, there were more viruses on Macs then on PCs. This was before the World Wide Web was invented, and e-mail attachments were virtually unknown. The viruses spread by floppy diskette exchanges, BBSes, and college networks.
There were at least half a dozen useful Mac anti-virus software packages, (Virex, Interferon being two of the biggies). We admins received our Virex upgrades via snail-mail (how’s that for quaint?)
WDEF, Word Macro viruses (an equal opportunity employer), nVir, all had their day.
So, the real long term Mac fanboys (and I still like Macs just fine) know that viruses can hit a Mac.
NOW, I would say that the difference between Windows and Macs/Linux/Unix/Solaris etc. is not so much in file structures or user permissions.
It is ActiveX. Microsoft wants the computers to do a LOT more automatically without a lot user interaction. The same tool that makes this happen in IE greatly increases the ease and variety of attacks that can be made on it.
Yep...prior to OS X macs were a mess. Crashing all the time, virus prone, and just garbage. Macbots think time began with OS X...the earlier OS’s don’t count. But they love to ding Windows XP, 2000, 9x, etc. But that’s like comparing OS 9 to XP, but instead they stack the latest and greatest OS X against XP. They need to compare windows 7 to OS X. And the past 3 years OS X was the first machine hacked in the pwn2Own contest.