Research group Gartner has said that Mac OS X users are now safer from a mass attack -- such as Blaster on Windows -- than they were two years ago, partly because Microsoft has closed so many holes in its ubiquitous platform.
Apple Mac users, who seem to be virtually immune from viruses, should still take care when installing software or applications from untrusted sources, according to Gartner.
In March 2005, in a report titled "Don't Assume Your Macs Are Immune to Security Flaws", Gartner vice president and research fellow Martin Reynolds warned businesses reliant on Mac systems to beware of "spyware infestations" and highlighted the potential of a hybrid virus that would attack both OS X and Windows.
On Friday, Reynolds said that 18 months on from his original prediction -- although OS X was far less likely to be the target of a hybrid worm -- Mac users were still vulnerable to keyloggers and other forms of spyware.
"Two years ago, a hybrid worm would have been a huge threat -- but the worm writers aren't that smart. With Windows largely closed up, mass attacks have stopped," he told ZDNet Australia in an e-mail interview.
"The Mac alone does not have a dense enough population to support a mass attack -- only one in 50 or so PCs is a Mac. Therefore, the risk of a mass attack is minimal. It is the targeted attacks that are a concern."
According to Reynolds, Apple's move to Intel means OS X now shares some common code with Windows, which could also open the platform to vulnerabilities.
"Moving to x86 means that the Mac shares some common code with the PC -- example, network drivers. These drivers opened up a target attack weakness in the Mac that was discovered because the drivers have common components," said Reynolds.
Spyware continues to be a concern for Mac users, according to Reynolds, who said that although OS X provided decent protection for its users, it could be overridden.
"Targeted attacks are difficult to prevent because many of them look like something that a user would do. The Mac OS puts good security around user activity, but this can still be overridden.
"Bottom line: pay attention to odd behaviour from any computer, it could be a hacker after your stuff. Don't just authorise anything that asks, think about it first," he added.
Last month, antivirus firm Symantec published its 10th Internet Threat Report and quietly admitted a few days later that its predictions of increasing Mac-targeted spyware threats have not been realised.