Best Mac Antivirus Software
You need an antivirus program on your Mac. That statement may cause some Apple users to shake their heads in disbelief, but with the amount of Mac malware on the Internet today, this fact is no longer up for debate.
In 2012, there was the Flashback Trojan that infected 600,000 Macs. In 2013, a targeted attack hit OS X developers at Microsoft, Facebook, Twitter and Apple itself. In 2015, the XCodeGhost attack poisoned hundreds of OS X and iOS apps. And in early 2016, the first known piece of encrypting ransomware for Macs appeared.
After evaluating six free and paid Mac antivirus products, Avira Free Mac Security is our top pick, thanks to its perfect malware-detection scores and intuitive interface. If you're willing to pay for Mac protection, Bitdefender Antivirus for Mac had the least impact on system performance of any solution we reviewed.
How We Tested
For all six Mac antivirus products we reviewed in this round, our testing was conducted on a mid-2012 15-inch MacBook Pro running OS X Yosemite 10.10.3. It was powered by a 2.3-GHz Intel Core i7 processor and had 4GB RAM.
Each antivirus software package was evaluated according to three criteria: efficacy against malware, performance impact and user experience. The latter included ease of use and of installation, as well as the usefulness of any extra features.
To gauge how effective each package was at stopping malware, we used the results of evaluations conducted by AV-TEST, a well-regarded independent product-testing lab in Germany. AV-TEST tested the Mac anti-malware engines of each brand to see how well each detected malware during both active scans (which AV-TEST calls "on-demand" scanning) and when files are opened, executed or downloaded (which AV-TEST refers to as "on-access").
Before we installed any AV software, we established performance baselines by running our custom OpenOffice spreadsheet test, which measures how quickly the computer's CPU can match 20,000 names with 20,000 corresponding addresses. The tests were run separately for accuracy. Each AV product was uninstalled before another was installed.
After installation of each package, we ran the OpenOffice test three times more — first without any active scan, then during quick scans and full-system scans. We then measured the performance impact by timing how much longer our spreadsheet test took to finish.