Even though Macs aren't as secure as you may have thought, there are plenty of ways you can protect your computer. In this battle, your first line of defense is yourself. Most security lapses can be prevented if you're conscientious about your surfing and what files you allow onto your computer.
For example, most malwares arrive in the form of Trojan horses, which come attached to e-mails or files you download from the Internet. This is a reference to the Greek epic "The Aenid," where the Greeks gave the Trojans a large wooden horse as a gift to honor the supposed Trojan victory over the Greeks. Greek soldiers poured out of the horse during the night to let the Greek army into Troy, taking the city by storm. Similarly, Trojan horse malwares are contained within seemingly benign files, like a note from a long-lost friend (who is fake) or a picture of a celebrity. Note that Trojan horse malwares are things you let in through negligence or poor judgment. In other words, be careful about what you click on in an e-mail, or what files you open if you're not sure about the source.
Look out for risky sites on the Web, too. Ever look at the status bar at the bottom of your browser? It'll usually show you the URL of the Web site you'll go to if you follow the link you're hovering over. If the link domain ends in .cc or .co, be careful. Viruses and other malware often originate from these domains [source: Keizer]. Regardless of the domain, use your common sense and take a look at a Web site's URL before clicking on any search results. Redirects based on popular search terms are a common trick too.
But don't worry, you're not alone in your fight against the bad guys. Legitimate Mac security software is out there. Intego, Kaspersky and Agile all offer highly rated security solutions you can buy to help you keep your Mac as clean and pure inside as it looks outside. Intego's VirusBarrier 6 offers basic protection for about $50, while Kaspersky's introductory software will run you about $60. Both offer comprehensive anti-malware protection, while Intego's version also includes a firewall. Agile is one of the highest rated password management tools available for $40.
If these are too pricey, Sophos and ClamXav are available for free. If you're new to anti-virus software (and most Mac users are) you might want to try a free option to learn more about what's available to you.