The previously impenetrable Mac OS now faces a malware program called the "MACDefender" and has prompted Apple to tell its users not to attempt to remove the software.

The "MACDefender" software has been marked by Apple as an "issue/investigation in progress". AppleCare does not provide support for removal of the malware.

In an internal memo obtained by Ed Bott of ZDNet, employees should not confirm or deny that the malware has been installed in the Mac. Apple representatives shouldn't send their customers to Apple stores as employees there do not remove malware.

Mac users have long been safe from viruses that frequently target Windows and other computer operating systems. These recent attacks on Mac users should be a wake-up call to Apple.

The MACDefender malware first gained notoriety this month when it was spotted by an anti-virus company. The program worms it way into Mac systems and automatically downloads in web browsers through JavaScript.

Users would have to agree to install the software and give an administrator password. The threat was categorized as low because of this feature but it has been shown that users are not aware that they are installing malware and install it to their computers.

The MACDefender spreads through search engines most notable Google using a method called "SEO poisoning". The sites are designed to appear first in search engine rankings by utilizing common search topics words. Attackers upload and implement scripts on the back end of websites. They inject common search terms and an iframe script that will send victims to other sites with malicious codes.

Users have advised infected victims to kill active processes from the application through Mac OS X Activity Monitor. MACDefender can be deleted from the Applications folder by dragging it to the trash. The best way to avoid a MACDefender is not to install any suspicious programs.