ClamXav for Mac Review

Once upon a time, if you wanted Mac antivirus software, ClamXav was one of your only options. The free open-source antivirus program, developed by Mark Allan since 2004, is a graphical user interface for running the ClamAV open-source antivirus engine.

Unfortunately, ClamXav hasn't kept up with other Mac antivirus options. We looked at five different Mac antivirus products, including the current ClamXav 2.6.4. When put to the test, ClamXav 2 … clammed up. We can't consider it one of the best Mac antivirus software programs.

MORE: Best Antivirus Software for Mac

Setup and interface

Setting up ClamXav 2 on my MacBook Air was quick and easy. The installer, available at clamxav.com, walks you through downloading the antivirus engine (which contains the malware detection) and setting up automatic updates. 

You can also get a slightly different version of ClamXav 2 from the Mac App Store. After installation, ClamXav 2 launches and begins its first definition update.

ClamXav 2 has the starkest interface of all the Mac antivirus programs we reviewed. It looks like another window of the Mac OS X's Finder; files being scanned are listed in alternating blue and white rows, as in older versions of Mac OS X and iTunes.

As free, open-source software, ClamXav doesn't come bundled with Windows or Android software the way some commercial programs do. For those platforms, check out our roundups of the best Mac antivirus software and the best Android antivirus apps.

Before starting a scan, you must choose which files on your hard drive you want scanned. You can either click the "+" button beneath the Source List in ClamXav 2, or navigate to the target file or volume and drag it right into the Source List. I dragged in the entire Macintosh HD volume.

To begin the scan, highlight the desired folder or volume in the Source List by clicking on it, and then click the green Start Scan button at the top of the window. ClamXav 2 has no prepared full-scan or quick-scan options.

The other buttons at the top of ClamXav 2's panel are for updating its list of virus definitions, viewing a log of scans, viewing a log of updates and a Preferences button. (In Preferences, you can create a whitelist of file types you don't want ClamXav 2 to scan.)

You can schedule anti-malware scans, but the scheduler is buried away under the Preferences button. (If you only glanced at ClamXav 2, you might think scheduled scans aren't possible.) Among other Mac antivirus tools, Sophos Antivirus for Mac Home Edition and Intego Mac Internet Security X8 also allow scheduled scans; Avast Free Antivirus for Mac and Bitdefender Antivirus for Mac do not.

Features and tools

One component of ClamXav 2, called ClamXav Sentry, automatically scans imported files as they're copied onto your Mac. For some reason, ClamXav Sentry only comes with the version of ClamXav 2 found on the ClamXav website. The App Store version of ClamXav 2 doesn't contain this feature, which we nonetheless considered very important. (The Mac antivirus programs from Avast, Bitdefender, Sophos and Intego have similar file-scanning features.)

In addition to scanning files, ClamXav 2 also has the option to scan email content for malicious attachments and phishing attempts.

ClamXav 2 is an antivirus scanner only, without extra features. It can't stop malware from installing itself via a drive-by browser download, for example. But it can also detect Windows malware on a Mac, as can the other Mac antivirus products we reviewed. Windows malware can't harm a Mac computer, but it can spread via Macs to other Windows computers.

ClamXav also doesn't have any kind of Web-link scanning component, for detecting malicious links and Web pages as you browse the Internet. Avast, Bitdefender and Sophos all have some form of this feature built into their products. ClamXav users could always cover this absence with a Web-link-scanning browser plugin, such as Bitdefender's TrafficLight, but ClamXav's lack of one counts against it.

Possibly because ClamXav is an ongoing open-source project, ClamXav 2 has next to nothing in the way of customer support. Users with questions will have to consult the ClamXav forums.

Security performance

Since ClamXav 2 is only an antivirus engine, it would need to have a very good malware-detection rate to compete with more fully featured programs that also include things like a Web-link scanner. We turned to independent German anti-malware testing lab AV-TEST to find out, but unfortunately, AV-TEST's latest evaluations of the top 18 Mac antivirus products didn't include ClamXav 2. We can't tell you exactly how it stacked up next to competing products from Avast, Bitdefender, Intego or Sophos.

System impact

No one wants an anti-malware program that slows down a computer while running scans. We tested each Mac antivirus program for its performance impact on a single MacBook Air.

On the Geekbench 3 benchmarking test, our Air scored 5,398 before any anti-malware programs were installed. During a ClamXav full scan (there's no quick-scan option), that score dropped to 3,989. That's a steep drop in performance, and it put ClamXav 2 in last place among the five programs we tested.

The software with the smallest system impact was Intego Mac Internet Security X8, with a full-scan score of 5,166, followed by Avast Free Antivirus for Mac (4,757), Sophos Antivirus for Mac Home Edition at (4,693) and Bitdefender Antivirus for Mac at (4,661).

Bottom line

ClamXav 2's saving grace is that it's free and open-source. Even so, there are better free options. If you are committed to open-source software, you probably already know you'll want to use ClamXav 2.

For anyone else, ClamXav 2's clunky interface, heavy system impact and near-total lack of extra features — even basic ones, like a Web scanner or on-access scanning—count strongly against the program. We recommend that users look at AvastFree Antivirus for Mac instead.

Jill Scharr is a staff writer for Tom's Guide, where she regularly covers security, 3D printing and video games. You can email Jill at jscharr@tomsguide.com, or follow her on Twitter @JillScharr and on Google+. Follow us @tomsguide, on Facebook and on Google+.