Yet another new variant of the Flashback Trojan for the Mac has been discovered in the wild, says security firm F-Secure. Called Flashback.K, the new version is said to be dangerous not only because it can infect a Mac without an admin password, but because it relies on a Java vulnerability that has so far gone unfixed in OS X, even though Oracle itself has closed the hole. Apple distributes Mac Java updates on its own timetable.