If there was one all-time advantage of the Mac OS over Windows, it was in the lack of viruses, trojans, worms and all such anomalies. Windows is prone to such attacks and Microsoft has had to release patches time and again to rectify them. But Mac OS X is now under attack by a trojan which is popularly called ‘Flashback’. As per the latest estimates by Dr Web, over 600,000 Macs have been affected.

The trojan exploits a loophole in Java Virtual Machine. It poses as an installer for Adobe’s Flash Player, which when installed for Safari, the malware reports back to a central server. It was reportedly designed to steal and transmit usernames and passwords of the users. There already was a fix provided by Oracle but Apple didn’t bother to distribute it. But the latest fix from Apple should fix it (10.6 and 10.7). Kaspersky Labs has also provided a free tool to remove the malware.

This is not the first time Mac OS has been attacked, though it has occurred rarely. The Inquirer has now reported that another similar malware named as Backdoor.OSX.SabPub.a by Kaspersky Labs. It too exploits the JVM loopholes and does not require any user-interaction to attack the host. This negates the popular belief that Macs are impervious to viruses and malwares. Even the Safari browser has been criticized for its large number of vulnerabilities.