http://www.theregister.co.uk/2012/06/26/apple_computer_virus/
Even Apples sometimes have worms in them admits Cupertino
Mac computers can be buggy, Apple has finally admitted. Two days ago the firm quietly pulled the claim that the iOS PCs are immune to viruses from its website. The purveyor of shinier-more-expensive desktops has replaced its former claim with the more cautious statement that Macs are "built to be safe".
The change was made to Apple's website on Sunday, according to Sophos. Apple's site now lists features which make Macs "safer" – including download alerts, security updates and data encryption.
The previous write-up claimed: "It doesn't get PC viruses. A Mac doesn't get the thousands of viruses plaguing Windows-based computers."
Macs were notably breached by the Flashback Trojan early this year.
http://www.theregister.co.uk/2012/04/11/apple_snubs_mac_botnet_fighter/
http://news.drweb.com/?i=2353&c=5&lng=en&p=0
BackDoor.Flashback.39 epidemic chronology
News that an outbreak of BackDoor.Flashback.39 has infected over 650,000 computers running Mac OS X spread quickly throughout the world