"We have removed the knowledge base article because it was old and inaccurate," said Monica Sarkar, an Apple spokesperson. "Mac is designed with built-in technologies to provide protection against malicious software and security threats right out of the box. Since no system can be 100 percent immune from every threat, running antivirus software may offer additional protection."

Apple had posted the article on its support site, encouraging Mac owners to run antivirus software only to turn around, pull it, and say it was a mistake.

Apple in the article had encouraged the widespread use of multiple antivirus utilities so that virus programmers will have more than one application to battle, making virus coding more challenging. In the article, Apple also suggested running three applications -- Intego VirusBarrier X5, McAffee VirusScan for Mac, and Symantec Norton Antivirus 11 for Macintosh.

Tissue and Antivirus Apps

Apple's article drew a lot of attention, especially since the company's latest television commercial included a person representing a PC sneezing and saying it has caught the latest virus. The person representing the Mac hands a tissue to the sniffling PC before it crashes.

Now it's Apple that might need the tissue after dealing with its own errors and after officials said no operating system is completely safe from all threats.

In fact, Apple's Web site tells consumers that no computer using the Internet is 100 percent immune to viruses and spyware. It goes on to say that the Mac is built on a solid UNIX foundation and designed with security in mind. It also says its Safari Web browser alerts Mac users whenever an application is downloaded.

Apple Not Immune

Reports from security company F-Secure show that 100 or so viruses were written for the Mac OS this year, and 850,000 for Microsoft Windows . But F-Secure also found two Trojan viruses that had a great impact on Mac users, including the PokerStealer Trojan and the AppleScript Trojan Horse Template.

The Trojan Horse affected Mac OS X 10.4 and 10.5 and was distributed from a hacker Web site, according to MacSecure. A discussion on the hacker site focused on distributing the virus through the iChat and Limewire applications. The virus ran hidden on a Mac system and allowed the hacker complete remote access, sent user and system passwords, and avoided detection by opening ports in the firewall.