When you drill down into the blurb, it adds "Built-in defenses in OS X keep you safe from unknowingly downloading malicious software on your Mac." A comparison of the "prior message" and the "current one" is shown above.
We've been saying it for some time. It's not as though Apple's OS X operating system is invulnerable to malware. Instead, it has "not been targeted" by hackers because its market share was simply not enough to generate interest.
Now that Apple has made inroads, criminals have become more interested in infecting Apple hardware.
Sophos U.S. senior technology consultant Graham Cluley said this was a positive sign, as faux messages about invulnerability tend to give less technical consumers a sense of bravado:
"I view the changes in the messages pushed out by their marketing department as some important baby-steps. Let's hope more Apple Mac owners are also learning to take important security steps -- such as installing antivirus protection."
Those of us who have a more technical background have already been following through with antivirus protection. Naturally, companies using Macs have already been doing so, as well.
While the sheer number of viruses that are available to invade Macs are far smaller than that on Windows, it's still necessary to feel a sense of caution when using your Mac, despite Apple's former message and older ads to the contrary (see below).