Apple closes a trojan loophole after 550,000 Macs are infected

Compare to Windows, OS X is nearly malware free. But it does run JavaScript.

Having written several times -- and taken a lot of heat from PC users -- about the relative security of Apple's (AAPL) operating systems (See Why are there no Mac viruses), I feel obliged to report that Mac OS X is under what appears to be the most serious malware attack to date.

According to a report posted Wednesday by Dr. Web, a Russian anti-virus vendor that may have a stick in this fire, the security of more than 550,000 Macs around the world have been compromised by the Flashback trojan.

Dr. Web, which sells an antidote for the versions of Flashback that run on Microsoft (MSFT) Windows machines, describes the Mac variant like this:        Full Read