From USA TODAY:
The first worm targeting Apple Computer’s Mac OS X operating system has surfaced, though it does not appear to be widespread or especially dangerous.
Its emergence, however, could indicate that hackers — who have almost exclusively targeted the much-larger Windows PC market — are expanding their attacks, computer-security experts say.
The so-called OSX.Leap.A worm is designed to spread over iChat, Apple’s instant-messaging system. Security experts call it the first notable Mac worm in several years, surfacing in a forum on the popular MacRumorswebsite on Feb. 13.
When launched, it can damage software applications and the operating system, says Vincent Weafer, senior director of Symantec Security Response.
Writers of malicious software code have historically ignored Macs because about 95% of the world’s PCs are Windows-based.
There are hundreds of thousands of viruses and worms aimed at Windows machines.