Apple has removed an old item from its support site late Tuesday in the US that urged Mac customers to use multiple antivirus utilities and this week said the Mac is safe "out of the box".

An Apple spokesman said: "We have removed the KnowledgeBase article because it was 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. However, since no system can be 100 per cent immune from every threat, running antivirus software may offer additional protection."

Apple's previous security message in its KnowledgeBase, which serves as a tutorial for Mac users, was: "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."

Security experts, while pleased that Apple urged Mac users to install antivirus software, had warned that running multiple antivirus products could cause problems and recommended against it.

Apple's antivirus support note was initially published last year and was updated last month, despite reports that it was a new note.

One Apple expert speculated that Apple was merely removing a poorly worded support note and said it probably wasn't ever Apple's intention to tell Mac users they need antivirus.

Rich Mogull, security editor of Apple news site TidBITS, said: "I bet you it was a low-level support note and it hadn't gone through the right approvals. That's my guess."

To some, Apple's latest move could be seen as back-tracking, given that it comes one day after those misleading reports circulated. The motive remains unclear, particularly because Apple didn't replace the previously published suggestion with an updated one.

The message that remains is that Mac users don't really need to take additional steps to protect against viruses and other malware. Telling customers they can run antivirus for "additional protection" could be interpreted as a way to protect against any liability.

There are no known viruses in the wild that exploit a vulnerability in the Mac OS, and Windows continues to be the overwhelming preference for malware writers to target their programs. But malware isn't just taking advantage of operating system weaknesses anymore. In fact, the majority of such threats now come from code that targets weaknesses in browsers and other applications that aren't platform specific.

Mogull said he doesn't recommend that the average Mac user install antivirus software because of the low-level of malicious software seen for Macs at this time.