WSJ.com - 'Worms' Turn on Apple Macs, Bigger Target as Sales Boom

Users of Apple Computer Inc.'s Macintosh computers have long enjoyed the technology equivalent of a safe neighborhood, where the viruses and security nuisances that bedevil far more common Windows PCs are practically nonexistent. Now, as the Mac is seeing some of its best sales in years, bad guys appear to be casing the joint.
In the past two weeks, information-security companies like Symantec Inc., Sophos PLC and McAfee Inc. have identified several security issues related to the latest version of Apple's Mac operating system, called OS X. Among the concerns: two 'worms,' programs written by unknown hackers that were designed to spread themselves to other Macs through Apple's iChat instant-messaging software and Bluetooth wireless-communications capability.
And in a reminder that Macs, like Microsoft Corp.'s Windows software, also contain potentially worrisome security holes, a German graduate student last week discovered a vulnerability in OS X that could let a hacker install potentially damaging code on a Mac through the systems' Safari Web browser