To deal with the issue of 'trojan user trickery,' Apple's new Snow Leopard operating system has enhanced the Mac platform with an "immune system," which prevents users from infecting their machines accidentally, while downloading supposedly-malicious Web content.

In an attempt to protect Mac users and their relative security, Apple has improved the safety admonitions that the users of Snow Leopard get when they direct download files or open disk images that contain files identified as 'malicious.'

While the Leopard also flagged Internet downloads with metadata that put users on the alert about Web-downloaded content, Snow Leopard has gone a step further with an additional warning to users when they open disk images that have been recognized as malware installers.

The Apple move reflects its vigilance from potential exploits, even though Mac is relatively free from any notable malware threat - largely because it is difficult to write viral code for infecting Mac OS X, and Apple easily rolls out a patch if vulnerabilities are discovered.

In fact, noting that "Mac bugs aren't really valuable", Mac security expert Charlie Miller - with reference to the Pwn2Own contest - remarked: "I'd still recommend Macs for typical users as the odds of something targeting them are so low that they might go years without seeing any malware, even though if an attacker cared to target them it would be easier for them."