Mac users may not see the infamous Blue Screen of Death that Windows users fear, but they are susceptible to viruses of their own.

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Are Macs really better than PCs at beating viruses?

No computer system is immune to viruses (at least not yet). After all, viruses are just programs and all computers were designed to run programs. But Macs have had several factors in their favor in the fight to stay healthy?

Some suggest that Macs keep such a stellar reputation due to market share [source: Poremba]. Who'd want to write a virus for 100 computers when you could reach 1 million? The disparity isn't that big between the number of Macs and PCs, but you get the point. Not everyone agrees with the market share theory, though, claiming that Macs really do offer fewer opportunities for malicious code to spread [source: Porten]. The bottom line: Macs are not invulnerable and can get infected.

Another myth revolves around the UNIX foundation of Mac OSX (Mac operating system ten). Architecturally, UNIX is built with a more robust permission structure that prevents unauthorized execution of software. While Microsoft Windows will try to run a program any way it can, even if a virus is redirecting things, UNIX will stop in its tracks when it detects an unauthorized redirection and limit any damage [source: Perrin]. This is great, but it doesn't make your computer immune. It's similar to how exercising and eating right will help you stay healthier, but if a strong enough flu bug comes around you're still in for some misery. To infect a Mac, the viruses just need to be written well enough to get around the architecture. Not easy, but completely do-able [source: Rooney].

Even Apple devotees are beginning to realize that Macs are not only vulnerable, but increasingly likely to be targeted by crackers. Trying to capitalize on this vague awareness, in 2011, someone released a Trojan called Mac Defender, a fake program that tried to pass itself off as anti-virus software. Once it gets onto your computer, it throws an annoying array of pop-up ads at you until you buy the fake software. It's not likely to fool many people, but it's still annoying and a sign of more to come.

Just because Macs are vulnerable doesn't mean all hope is lost. Let's look at some effective ways to keep your Mac and your data secure.