The biggest vulnerability to Macintosh computers is the belief among their devoted users that Apple's superior operating system makes them immune to malware, experts say.
"Some Mac users have this perception that the Mac is free from hacks, and that is completely wrong," said Zheng Bu, senior director of research for FireEye, which develops antimalware products.
Last year, the Flashback Trojan malware infected an estimated 600,000 Macs by appearing to be a browser plug-in but actually stole personal information. In February, Apple said Macs operated by Apple employees were infected with Java-related malware when they visited a software development website.
One of the biggest threats to Mac users is third-party software, such as Java, a popular vehicle for cyber thieves to infect Windows and Mac machines by writing only one attack code. In such cases, simply visiting an infected website that exploits a Java vulnerability can enable malware to get onto a Mac.
Adobe software is another vehicle used by hackers to infect computers.