Apple finally released a security update that protects against the infamous MacDefender, a malware that pretends to be antivirus software that keeps malware and viruses away from Mac.

Released on Tuesday, the security update for Mac OS X 10.6.7 and Mac OS X Server 10.6.7 identifies and removes the system-crippling class of antivirus malware called MacDefender.

MacDefender, which is identified as a sort of Trojan Horse scareware, warns the users of the targeted computer that his/her machine is infected with malware, and suggests the user to download and install antivirus software.

Once downloaded and installed, the bogus antivirus software infects the computer, takes over the desktop and wrecks all kinds of havoc on the computer. In some cases, pornographic sites start popping up on the screen.

The fake software is hard to get rid of as it attaches itself to the launch menu and dos not feature any dock icon.

One can get update by clicking on "Software Update" under the Apple menu. It can also be downloaded from Apple's support site. The update will stop the malware, wipe out persistent files, and address any changes made by the MacDefender.