Free Malware, Spyware, and Adware Protection

The question isn’t whether you can afford to install antivirus software. It’s whether you can afford not to. Maybe you’re not working right now, instead living from your savings…but what if a banking Trojan siphons off your cash to a money launderer across the world? Perhaps you’re taking advantage of sheltering in place to finally finish that novel. You’ll scream with anguish if ransomware turns your brilliant prose into gibberish. Whether you’re fine working from home or are an essential worker who's scrimping to make rent, you can still protect yourself by installing a free antivirus utility. We’ve evaluated plenty of them to help you choose the one that’s best for you.

Your antivirus should definitely have the ability to root out existing malware, but its ongoing task is to prevent ransomware, botnets, Trojans, and other types of nasty programs from getting a foothold. All of the antivirus programs in this collection offer real-time malware protection. Some take the fight to the browser, working hard to ensure you never even browse to a malware-hosting site, or get fooled into turning over your credentials to a phishing site.

Free Antivirus vs. Paid Antivirus

If free antivirus tools are so great, why should anybody pay? For one thing, quite a few of these products are free only for noncommercial use; if you want to protect your business, you must pony up for the paid edition. At that point, you should probably consider upgrading to a full security suite. After all, it's your business's security on the line.

Even for personal use, most for-pay antivirus tools offer more than their free counterparts—sometimes a lot more. For example, ZoneAlarm's paid edition adds protection against malicious and fraudulent websites that the free version lacks. And Panda reserves quite a few features for paying customers, among them firewall protection, application control, cross-platform support, and detection of insecure Wi-Fi connections.

In addition, many companies don't offer full-scale tech support for users of the free edition. The first time you need extra help digging a particularly stubborn piece of malware out of your system, you might regret the lack of support.

Independent Antivirus Lab Test Results

Around the world, researchers at independent antivirus testing labs spend their days putting antivirus tools to the test. Some of these labs regularly release public reports on their findings. We follow four such labs closely: AV-Comparatives, MRG-Effitas, SE Labs, and AV-Test Institute. We also take note of whether vendors have contracted for certification by ICSA Labs and West Coast Labs.

Security companies typically pay for the privilege of being included in testing. In return, the labs supply them with detailed reports that can help improve their products. The number of labs that include a particular vendor serves as a measure of significance. In each case, the lab considered the product important enough to test, and the vendor felt the price was worthwhile. The labs don't necessarily test a vendor's free product, but most vendors pack full protection into the free product, enhancing premium versions with additional features.

We Test Malware Protection

In addition to carefully perusing results from the independent labs, we also run our own hands-on malware protection test. We expose each antivirus to a collection of malware samples, including a variety of different malware types, and note its reaction. Typically, the antivirus will wipe out most of the samples on sight, and detect some of the remaining ones when we try to launch them. We derive a malware blocking score from 0 to 10 points based on how thoroughly the antivirus protects the test system from these samples.

Since we use the same samples month after month, the malware-blocking test doesn't measure a product's ability to detect brand-new threats. In a separate test, we attempt to download malware from 100 very new malicious URLs supplied by London-based testing lab MRG-Effitas, typically less than a few days old. We note whether the antivirus blocked all access to the URL, wiped out the malicious payload during download, or did nothing. Sophos Home Free managed 100 percent protection in its latest test, as did McAfee and Vipre.

If you're interested in learning more about our testing techniques, you're welcome to read more about how we test security software.

Useful Features

Just about every antivirus product scans files on access to make sure malware can't launch, and also scans the entire system on demand, or on a schedule you set. Once that cleaning and scheduling is done, blocking all access to malware-hosting URLs is another good way to avoid trouble. Many products extend that protection to also steer users away from fraudulent websites, phishing sites that try to steal login credentials for financial sites and other sensitive sites. A few rate links in search results, flagging any dangerous or iffy ones.

Behavior-based detection, a feature of some antivirus products, is a two-edged sword. On the one hand, it can detect malware that's never been seen before. On the other hand, if it's not done right, it can baffle the user with messages about perfectly legitimate programs.

Any antivirus should eliminate spyware along with other types of malware, but some products include features designed specifically for spyware protection. Features like encryption to protect your sensitive data and webcam control to prevent remote peeping typically show up in commercial products, not free ones. But some free products include features like a simple on-screen keyboard to foil keyloggers.

One easy way to keep your PC protected is to install all security updates, both for Windows and for browsers and other popular applications. Windows 10 makes it easier than ever to stay up to date, but there are plenty of security holes in older Windows versions, in popular apps, and in add-ons. Scanning for vulnerabilities in the form of missing updates is a feature most often found in commercial antivirus products, but it does turn up in some free ones. In the list below you can see which products include these useful features.

What's Not Here?

This article reports only on free antivirus products that received at least a good rating in our reviews—three stars or better. Microsoft Windows Defender Security Center joined the party with a three-star score not long ago; it's now at 3.5 stars. Yes, it's more of a Windows component than a free product. Yes, the very best free antivirus utilities offer many more layers of protection. But Windows Defender protects everyone who can't be bothered to install a third-party antivirus tool.

Several free utilities devoted entirely to ransomware protection have come on the scene in the last few years. Alas, several of those have fallen by the wayside, among them Bitdefender Anti-Ransomware, Cybereason RansomFree, and CyberSight RansomStopper. In any case, these are useful companion products, but they don't do the job of a full-scale antivirus utility.

There are also numerous free antivirus utilities that work solely to clean up existing malware infestations. You bring out these cleanup-only tools when you have a nasty malware problem. When the malware's gone, they have no further use, since they offer no ongoing protection. Our favorite in this category is Malwarebytes Anti-Malware, and it's one you should try if you've got a malware problem. But since they're free, you can keep trying others if the first one doesn't do the job. When the scare is over, you'll need a full-blown antivirus for ongoing protection.

Which Free Antivirus Is Best?

Our current Editors' Choice for free antivirus utility is Kaspersky Security Cloud Free, which took near-perfect scores in recent tests. Avast Free includes some useful bonus features not found in Kaspersky, including a password manager and a network security scanner. However, due to a problem with sharing of user data between Avast and its subsidiary Jumpshot, we can't call it an Editors' Choice at present. If you do have a little cash in your budget for security, the best paid antivirus software does offer more and better protection. If not, try a few of these free tools and see which one you like best.

Worried you might already be infected? Check out our article on the signs you have malware.