Macs aren't immune to bugs: More than 600,000 Macs fell victim to the Mac Flashback Trojan in 2012, and hackers famously infected some Apple staffers' computers in 2013. The good news is: You can protect yourself for free. Sophos Anti-Virus for Mac works so well in tests, experts say there's no reason for most home Mac users to buy paid antivirus software.
Easy-to-install, minimalist design. Sophos Anti-Virus for Mac is a free app, downloadable from Sophos.com. Installation is a breeze, testers say. They don't try installing it on infected systems -- the Waterloo of many Windows antivirus programs -- which makes sense, as Macs don't catch viruses nearly as often and the vast majority of users will be installing the software on a clean Mac. Sophos "installs like any other Mac application, and uninstalls just as easily," says Alan Henry at Lifehacker.com. Experts at AV-Comparatives.org agree: "We found the installation process very straightforward." Henry likes Sophos' "compact, easy-to-use interface," but it's a little too minimalist for AV-Comparatives.org's taste. Testers there wish for a status display and an "update now" button.
You decide how often to scan. Sophos has two features that are missing on most Mac antivirus software: It blocks both Windows and Mac malware (so you won't pass infections to your Windows friends), and it lets you schedule regular scans (to occur silently, in the background). Of course, you can also scan your entire Mac (or just specified files, folders or drives) at any time. Or, you can set Sophos to scan every file you try to open (including emails and USB drives). If the file is malicious, Sophos will stop you from opening it. Sophos also includes a web security filter. It stops you from visiting malware-infested websites, and it blocks any malware that you download from the Internet.
Blocks both Mac and Windows malware. Protection is impressive. AV-Comparatives.org peppers Sophos with 20 malicious Mac apps ("a substantial part" of Mac malware from the first half of 2013) and 500 "very prevalent" Windows malware samples. Sophos catches every single one. Moment-by-moment updates mean the app's knowledge base never grows stale. "The moment new threats are detected or found in the wild," your app will know about them, says Henry at Lifehacker.com. Suspicious, unknown files get quarantined. "Best of all, though, in our testing, Sophos was one of the most resource-light antivirus apps on the Mac, which is impressive considering the features it offers," Henry says. Some users complain that it bogs down their systems, but user reviews are too few to draw any real conclusions.