The change comes after more than half-a-million Macs were infected with the Flashback Trojan virus earlier this year.

Apple's web page titled 'Why you'll love a Mac' used to state that: "It doesn’t get PC viruses. A Mac isn't susceptible to the thousands of viruses plaguing Windows-based computers. That's thanks to built-in defences in Mac OS X that keep you safe without any work on your part. With virtually no effort on your part, OS X defends against viruses and other malicious applications, or malware."

The website has been altered and now simply says: "It's built to be safe."

"Built-in defences in OS X keep you safe from unknowingly downloading malicious software on your Mac," the website continues. "OS X is designed with powerful, advanced technologies that work hard to keep your Mac safe."

But there is no longer any reference to Macs being immune from the viruses long-suffered by PC users.

Apple declined to comment on the alteration when asked by this website.

The change in the company's marketing, which was made quietly at the end of last month, was welcomed by security experts.

"People in glass houses shouldn't throw stones," said Graham Cluley from British security firm Sophos.

"Let's hope more Apple Mac owners are also learning to take important security steps - such as installing anti-virus protection."

Many security experts have said that both Apple and its users have underestimated the threats they face from viruses and hackers in the past.

The machines' supposed security - whether real or not - has long been a selling point for Macs. But as Apple's market penetration has increased significantly in recent years, so too have the security risks.

Anti-virus software companies reported an increase in sales for Mac security software following the outbreak of Flashback in April this year.

Apple also drew criticism for failing to release a fix for the virus until three months after it was discovered.

But the company may be taking security more seriously after the breach, with a Gatekeeper feature in the new Mac operating system Mountain Lion, which is slated for release as early as next week.

Gatekeeper creates permissions for only trusted sites and developers' apps to be downloaded and installed, though the feature can be disabled.

This latest backflip from Apple comes after the company was recently forced to drop claims in Australia and Britain that the new iPad had 4G capabilities.