A second bit of malware targeting Apple's Mac OS X operating system (it would ostensibly use short-distance Bluetooth wireless networking technology to spread) has been spotted by F-Secure, Playfuls.com reports. The Java-based Inqtana.A is, apparently, an essentially ineffectual worm and has not been let loose in the wild. Its real significance seems to be in proving that last week's Leap-A, the first real virus targeting the Mac OS, was not an aberration.

MacWorld writes that Inqtana.A, a "proof of concept" virus, has an internal counter that renders it inoperative after February 24, and Apple has patched the vulnerability in free system updates.

According to Playfuls, a Sophos web poll of 600-plus computer users after Leap-A's discovery found that 79 percent believe Mac computers will be targeted more in future, though more than half said they did not believe the problem would be as great as for Windows, and 21 percent believe the threat against Macs will not grow.