Last Updated on November 21, 2018 by Dave Farquhar
What’s the best free antivirus? I have an answer that may surprise you. I also have a supplement that may surprise you. And I have a third supplement you already have but probably never heard of.
Keep something in mind. I don’t like using words like “good” and “best” in the same sentence as antivirus software. Imagine a college graduating class whose valedictorian is Chris Farley’s character from the movie Tommy Boy. What you want from your antivirus software is something that doesn’t do a lot of damage.
The worst thing antivirus software can do is try to do too much. There’s a name for problems in antivirus software. Professional hackers call it the “confused deputy” problem. Confuse the deputy, and you can get it to use its power for evil instead of good. The best way to avoid the confused deputy is to keep the deputy simple.
If you’re running Windows 7, I recommend Microsoft Security Essentials. If you’re running Windows 10, I recommend the built-in Windows Defender. (Note that Windows Defender on Windows 7 isn’t an antivirus program.)
Now let’s talk about supplementing your antivirus. It’s possible to run a second antivirus program as strictly a scanner. I no longer recommend this practice. Many people believe a second antivirus program will catch things the first one will miss. It can, but in my experience, something that gets past one antivirus program will probably get by 75% of them. So you don’t gain much by running just one.
The other day a former coworker reminded me of a great trick: Process Explorer. It’s also free.
Instead of running a second antivirus solution, I recommend installing Process Explorer. Run it, then navigate to Options and click on Virustotal.com. This enables Process Explorer to submit your running programs to Virustotal.com, which will scan those processes with more than 50 antivirus engines. A process detected by none of them is probably not worth worrying about. What about one? Potentially malicious. A process detected by more than one is almost certainly malicious. Emerging malware may only be detected by a few. I’ve caught malware samples that 16 or fewer of 54 detected.
And the nice thing about running Process Explorer is that if you submit your running processes, it improves your other antivirus software. Google shares Virustotal data with all of the AV vendors.
Yes, Process Explorer is a rare instance of Microsoft and Google working together.
You can click Options and select Replace Task Manager. It’s up to you if you want to do that. Under Windows 7, I certainly would. Windows 7 still has the Task Manager from the mid 1990s. Windows 10’s Task Manager has some network functionality that Process Explorer doesn’t, so I’m torn when it comes to replacing Windows 10 Task Manager with Process Explorer.
But if your system is acting strange at all, fire up Process Explorer and see if anything suspicious is running. It gives you all of the benefit of running 54 antivirus programs, without the problems.
If you want yet another layer of defense, here’s a nifty trick with the Malicious Software Removal Tool. It’s a little more protection, with nothing more to download.
That’s all you need for the best free antivirus protection. This trio will outperform most paid solutions, and annoy you a lot less. To give them a little extra help, change your DNS to Cleanbrowsing.org’s servers.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.
What’s your opinion on using linux as an antivirus? Do you need to add something to the OS?
I’d say there’s less reason on Linux, but the reason isn’t obvious. On Linux, almost all software comes from a trusted repository. You run apt or yum to download and install your software, rather than downloading it from sketchy websites who inject malware into downloads as part of their business model. Or worse yet, downloading pirated cracked software that includes unexpected surprises. A lot of people who should know better do that, and brag about it.
If you pirate movies and music and stuff like that, you still run the risk of infection, and good luck finding a Linux antivirus program that detects anything. If you don’t engage in risky behavior, then I suppose you’re reasonably safe without AV, and it’s not like the Linux-based AV programs actually find much. I behave myself on Windows, and my AV only fires every few years.
You do need to make sure your Linux box is installing updates automatically like a Windows machine though. There’s no shortage of vulnerable software on Linux. OS partisans argue all the time that their favorite OS is more secure because it got fewer updates in a given year, but it only takes one.
Thank You.