Apple encourages the widespread use of multiple antivirus utilities so that virus programmers have more than one application to circumvent, thus making the whole virus writing process more difficult.
It’s pretty tempting, but I’ll leave the jokes about how ironic this is and the posting of Apple commercials making fun of PC users with viruses to others. Still, this leaves you wondering when the first Linux distribution will start to offer the same advice.
While MacOS, Linux and other UNIX systems have long enjoyed relative security because a normal user is granted less rights by default, that advantage is disappearing fast. With Vista’s UAC system, malware makers have to revert to social engineering to get users to load their virus, and if you can get a user to bypass UAC protection, you can also adapt that technique to work with sudo and other tools. Virus writers are generally going for the low-hanging fruit, and while Vista isn’t perfect, it is getting harder to attack, thus making other targets more attractive.
The other advantage, being the lower market share of Linux and MacOS, is also fading fast. MacOS in particular is gaining market share fast; according to my statistics, 9.1% of all visitors to this site were using MacOS last month, with Linux not far behind (7.6%). So the UNIX-based operating systems add up to about 17%; that’s almost as much as Windows Vista (18.8%).