Both threats were classified as ‘low risk’.
The first worm, the OSX/Leap-A worm, was revealed on Thursday, amid warnings that it spreads via instant messaging systems
"Some owners of Mac computers have held the belief that Mac OS X is incapable of harbouring computer viruses, but Leap-A will leave them shell-shocked, as it shows that the malware threat on Mac OS X is real," said Graham Cluley, senior technology consultant for security firm Sophos. "Mac users shouldn't think it's okay to lie back and not worry about viruses."
The worm attempts to send itself to contacts on the infected users' buddy list. But according to rival security firm Symantec, a bug in the worm's code reduces the chances of propagation. There have been a small number of infections reported.
On Friday, a second worm, known as the OSX/Inqtana-A worm was identified. This, according to Sophos, is a proof-of-concept worm that exploits a Bluetooth vulnerability. That vulnerability has already been patched by Apple – again reducing the chances of widespread infection.
"It's disturbing to see a second worm for Mac OS X so soon after the first, but it should be remembered that this is only two compared to well over 100,000 viruses for Microsoft operating systems," said Cluley.
As always, the advice for Mac and Windows users alike is to keep anti-virus and firewall software updated, and to be careful when opening attachments.