Apple has removed a widely publicized support document from its website that encouraged Mac OS X users to install antivirus software, explaining that its operating system was designed with safeguards to protect against malicious attacks on its own.

The recommendation drew widespread attention given that the Mac maker has been critical in its television advertisements of Windows users' need to stock up on virus detection software while its own computers remain immune to viral threats.

It was later revealed that the document was about a year old and only caught the attention of industry watchers after Apple recently updated it to reflect changes in the version numbering of the antivirus software it was recommending.

"Apple encourages the widespread use of multiple antivirus utilities so that virus programmers have more than one application to circumvent, thus making the whole virus writing process more difficult," the document said, in part.

Speaking to CNet News.com, Apple spokesperson Bill Evans said the article was removed last night because it was deemed to be "old and inaccurate."

"The Mac is designed with built-in technologies that provide protection against malicious software and security threats right out of the box," he said. "However, since no system can be 100 percent immune from every threat, running antivirus software may offer additional protection."

TidBITS security editor Rich Mogull speculates that Apple may have never intended to urge Mac users to install antivirus software, and that the support article may have found its way to the company's website without being filtered through the proper channels.