A second strain of malware targeting Mac OS X has been discovered days after a Mac OS X Trojan appeared on the scene. The latest malware, Inqtana-A, is a proof-of-concept worm that attempts to spread using a Bluetooth vulnerability.

The worm is not spreading in the wild and uses an internal counter that means it will expire on February 24, so it's unlikely to ever be much of a problem. Nonetheless, Mac OS X 10.4 (Tiger) users are still advised to make sure they're patched up in order to guard against attack from any future worm that uses the same exploit.

Earlier this week, security researchers discovered a Trojan (or what many are classifying as a worm), dubbed Leap-A (AKA Oomp-A), that spreads via the iChat instant messaging system. Mac fans have to unzip the file and enter security codes to run it so that, in practice, Leap is also scarcely much of a threat. Most anti-virus vendors categorise it - like Inqtana - as low risk. ®

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