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How we test antivirus software

By Adam Marshall

See the lengths we go to make sure that the internet security software you install on your PC or Mac will keep you protected from malware and scams.

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What makes Best Buy antivirus software?

When you download virus protection - whether it’s paid-for or free software - you want to feel confident that hordes of internet nasties will be safely locked out of your PC or Mac.

To ensure that security software packages offer good protection against day-to-day threats, we put together a horrible collection of old and new viruses and other malicious downloads, also known as malware. A Best Buy security suite will keep your computer as safe as Fort Knox.

But there’s more to internet security than just fighting malware. So our thorough testing considers other key questions you’ll be asking before you download, including:

  • Will I be shielded from viruses?
  • Will it help me avoid scams?
  • Is the software easy to install and use?
  • Does it include all the features I need?
  • Will it slow down my computer?
  • Should I download it?

Head on to our antivirus software reviews or read on to find out more about how our independent testing works.

Will I be shielded from viruses?

We use the latest malware to try to infect our test computers. Using virus-ravaged zipped email file attachments, USB sticks and website downloads, we carry out a full-on cyber assault on the software. And for Macs, we check to see whether they stop annoying adware, too. The security packages that deal with the threats with the most effectiveness and least fuss score the highest marks and earn a place in our run-down of best antivirus programs.

We also check the programs to ensure they don’t let you pass infected files onto other people, even if the files haven’t been opened by you first.

Will it help me avoid scams?

Security suites are subjected to 25 spam webpages and emails, to see whether they flag the potential dangers. We click on links contained in phishing emails – hoax emails sent in the hope that the recipient will enter confidential information – to see whether the software stops us from proceeding to these dangerous scam websites designed to lift user data or infect machines.

We throw in a few genuine emails too, to make sure that the software doesn’t waste your time by flagging emails and websites that are clearly safe for you to access.

Is the software easy to install and use?

It's all very well for a security software program to pick up every virus and spam email that's out there, but it still needs to be easy to use and unobtrusive.

We look for security software that not only identifies threats, but warns you clearly and talks to you in jargon-free language as you go through the removal process. Points are deducted for confusing or scaremongering alerts and any ambiguous action that could compromise security.

Before that, we buy and install each security software package on a ‘fresh’ computer, and rate this process while looking out for complications and attempts to sell you more products. Plus, we rate the initial software set-up process and first scan, looking to see if it's easy for a beginner to set up properly.

Whether it's software that you pay for, or a package vying to be one of our best free antivirus downloads, we'll tell you if it's easy enough to use.

Does it include all the features I need?

The main thing that separates paid-for and free antivirus software is the added extras that come with them. If you’re spending up to £60 a year on your protection, then you’ll want some bells and whistles to sweeten the deal.

So we tell you whether the program you’re eyeing up includes the likes of a firewall, parental controls, identity protection, backup and tune-up. And we don’t stop there – for each added extra, we tell you about its effectiveness and usefulness as well.

Will it slow down my computer?

Virus protection scans should operate silently and discreetly in the background while you get on with using your computer. The worst programs will reduce your system to a crawl while they carry out their routine virus checks.

We carry out a range of everyday tasks on our test computer while the software does its thing. If it takes an age to open a web browser or save files, then the software will lose marks.

Should I download it?

We combine the results of all these assessments when we calculate the total test score, so that we can tell you the software that combines the best of protection, ease-of-use and added features.

A premium is put on the package’s antivirus credentials since - first and foremost - it should be brilliant at keeping your PC or Mac free from malware. The final score breaks down as follows and doesn’t take price into account, so free downloads are judged on the same criteria as paid-for packages:

Ease of use…..35%

If a program receives a total test score of 76% or above, we’ll award it Best Buy status.


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