Although Macs are designed to make it difficult for viruses to work, there's no reason to assume your Mac is free of viruses. In 2012, security software company Sophos conducted a study of 100,000 Macs that downloaded its free security software and found that one in five carried Windows malware. While these programs can't affect your Mac, they could spread to Windows PCs. In the study, only 2.7 percent of the Macs were infected with Mac OS X malware, but as Mac sales grow, there's a chance programmers could create more Mac viruses. That makes checking your Mac for viruses all the more important, and there are several free and paid programs you can use.
1Install and run a free anti-virus program like ClamXav, Sophos, or Avast (links in Resources). Each of these can scan your Mac for viruses and malware and are regularly updated to ensure you're protected from the latest threats. Although each of these programs are slightly different, they enable you to do scans of your entire hard drive, create custom scans like your mailbox (Mbox) folders, or have the program run in the background to scan files as you open them.
2Run a more robust anti-virus software program like McAfee VirusScan for Mac or Norton Antivirus for Mac if you want more options and features and don't mind paying for anti-virus software. These can also be easier to operate if you're used to using their Windows products.
3Keep your Mac security up-to-date before installing an anti-virus program. To do this, click the Apple menu and select "Software Update." Once this is done, it's safe to run the anti-virus program. Note that doing a complete scan of your hard drive can take hours, depending on how many files are on your Mac. If the software detects a virus or malware, it will provide you with instructions on how to remove it.
4Navigate to the DNS Changer Working Group (www.dns-ok.us) to automatically check your Mac for Trojan spyware. The website automatically redirects you to the DNS Changer Working Group website (dcwg.org), which tells you if your computer is infected or not. If your computer is infected, the website provides you with steps to fix it. If it's not infected, you get a message telling you "Don't Panic!"
- Avoid using anti-virus software you're unfamiliar with, especially those appearing in pop-up ads warning you that you already have a virus. These are often malware programs designed to infect your computer rather than help you get rid of any viruses.