Apple Operating System Affected by Malware

Mac Defender Intego Security The Mac Defender software is designed to look authentic and asks users for their credit card information.

For years Apple Mac users have boasted about the lack of malware on their computers. In comparison, Microsoft Windows owners have regularly felt the brunt of viruses and malware that can easily debilitate an entire computer system in minutes.

Now Apple is in that camp too after a barrage of malware began infiltrating computers over the past few days.

To fix the problem, Apple posted a list of instructions on its Web site Wednesday telling users how to remove the intrusive software from Macs. The company also said it planned to offer a software update that would completely eliminate the malware in the coming days.

The malware infects Mac computers through Web sites that tell users to install antivirus software called Mac Defender. This software does the opposite of what it proposes and actually infects computers.

Apple said the ultimate goal of the software was to gain access to credit card information “which may be used for fraudulent purposes.” Alternative versions of the program are called MacProtector and MacSecurity.

The security company Intego posted an explanation of the malware on its blog and said the software was designed to look authentic and professional, using standard Apple iconography.

Intego explained that once installed, Mac Defender would open  pornographic Web sites in the user’s Web browser every few minutes. “This is most likely to make users think that they are infected by a virus, and that paying for Mac Defender will relieve them of the problem,” the company said.

Correction: May 26, 2011
Correcting references to the malicious software in question, which is not a virus. Thanks to readers Dr. Riley and Joe Holmes for pointing out the error.