Everyone might have heard that Apple had released a critical update to Java for Mac OS X which is meant for to fix dozen security holes and vulnerabilities in the program. This patch needs to fix the flaw that attackers used broadly to deploy malicious software. It is on both Windows and Mac. This update for java in Mac X Lion 2012-001 or Mac OS X 10.6 sews up an very serious security vulnerability. This flow has been used to plant the Flashback Trojan so that it can infect large numbers of Mac computers. The recent reports say that Flashback Trojan has successfully infected more than 550,000 Macs, and mostly in U.S. based systems. This has been confirmed by the Russian security firm.