According to a recent story on Network World, Apple Macintosh Computers running Mac OS X have been the target of cyber Malcode attacks:
What’s even more interesting is the degree of investment this ("hacker") team has made in OS X malcode. They’ll be making new infections, it seems, for some time to come with that configurable loader.
Adding to the problem is the immunity Macintosh users have felt to viruses and other threats. While Macs are the minority on the Internet they may be soft targets because they are quite often not protected.