Following April's Flashback Trojan - which hit more than 550,000 Macs - Apple recently removed from its website the claim that its Mac operating system is not susceptible to PC viruses.
The supporting text, meanwhile, no longer says: "A Mac isn't susceptible to the thousands of viruses plaguing Windows-based computers." That line has been deleted and now it says: "Built-in defenses in OS X keep you safe from unknowingly downloading malicious software on your Mac."
Apple did not immediately respond to request for comment.
Notes about Mac's "sandboxing" feature remain the same, explaining that the system thwarts hackers through a technique that restricts what actions Mac programs can perform.
"Clearly they've decided that pointing out the size of the Windows malware problem isn't going to look terribly convincing unless they are also open about that Mac malware also exists," Cluley wrote in a blog post.
He referred to the website changes as "important baby-steps."
"So, the problem is real," Cluley continued. "And Apple is becoming a little bolder in acknowledging it."
The Flashback Trojan made headlines in early April, with more than half a million Macs affected by the bug. About 56.6 per cent of the infected computers, or 303,449, were located in the US, while 19.8 per cent were in Canada, 12.8 per cent were in the U.K., and 6.1 per cent were in Australia, according to Doctor Web.
In addition to its reach, Flashback was notable because Apple had always touted its OS as less (or not at all) susceptible to the viruses that often hit Windows-based PCs. According to Kaspersky Lab, the spate of Mac-related malware did not indicate that Apple's OS was any more insecure than it was in the past, but was mainly the result of its growing popularity.
In Mac OS X Mountain Lion, which will be released next month, a feature known as Gatekeeper will let users choose their level of security in an effort to avoid malware. They can opt to only download Mac App Store apps, Mac App Store apps and those from identified developers, or applications from anywhere.