Is free antivirus safe? What official guidance says

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Genuine free antivirus exists, and you may already have it. The UK's National Cyber Security Centre (NCSC) says antivirus is often included for free in the operating systems that run Windows and Apple computers. Most of the official warnings are about fakes: pop-ups and adverts dressed up as security software.

Quick answer

The NCSC says there are paid and free antivirus products, and that Windows and Apple computers often include antivirus for free. Phones don't need it if apps come from official stores. Download only from an official app store or the developer's own website. Don't trust browser pop-ups offering scans, and never call a number in one.

Is free antivirus safe to use?

The NCSC lists free products alongside paid ones: it says there are a variety of commercial paid and free products available, and its advice is to make an informed choice.

The danger is software that only pretends to be antivirus. The US Cybersecurity and Infrastructure Security Agency (CISA) warns that adware pop-ups in your browser may disguise themselves as antivirus software.

What antivirus do I already have for free?

Check this before you download anything.

  • Windows. The NCSC names Windows Defender Antivirus, built into Windows. CISA says its antivirus protection is enabled by default.
  • Mac. The NCSC calls XProtect, macOS's built-in security software, reasonably effective at preventing malware. Apple describes it as built-in antivirus technology. More in does a Mac need antivirus.
  • iPhone and Android. The NCSC says you don't need antivirus on a smartphone or tablet, provided you only install apps from official stores such as Google Play and the Apple App Store. Android phones also have Google Play Protect, which Google says is on by default.

If you rely on the built-in antivirus, the NCSC says make sure it's switched on. It adds that doing so makes you instantly safer.

What's the catch with a free trial?

New computers often come with a trial of a separate antivirus product already installed, the NCSC says. When the trial ends, you'll have to pay or register to keep using it. It also warns that separate antivirus products won't always work alongside the built-in one, and could even stop it working completely.

How do I tell a real free antivirus from a fake?

Look at how it reached you. The official sources describe the fakes in similar terms.

  • A browser pop-up says you're infected. Apple says that if a pop-up or alert warns you about security problems or viruses on your device while you're browsing, don't believe it. These are usually fraudulent adverts.
  • It asks you to click to switch on scanning. CISA's example is a browser alert showing a red stop sign with an urgent message prompting you to click to enable antivirus scanning. It says to exercise extreme caution, because it may be malware.
  • It warns you without you having run anything. Google says to beware of warnings about viruses or infected devices, especially if you haven't recently used a virus scanner.
  • It gives a phone number. The US Federal Trade Commission (FTC) says real security pop-up warnings and messages will never ask you to call a phone number.
  • Someone contacts you first. The FTC says legitimate tech companies won't contact you by phone, email or text message to tell you about a problem. It describes scammers who ask for remote access to your computer, pretend to scan it for viruses, then offer to remove a problem for a fee.
  • It came from an advert. The FTC says scammers place bogus ads for software on social media sites and search engines, and advises not clicking ads to download software.

Apple's advice for any of these pop-ups: don't call the number or follow the links. Navigate away from the page, or close the whole window or tab. Some pop-ups have fake buttons that look like a close button, so if you're not sure, close the tab.

Where should I download free antivirus from?

From an official store or the developer itself.

  1. On a Mac, Apple says to install software from the App Store or get it directly from the developer's website.
  2. On iPhone or Android, use the App Store or Google Play. The NCSC's advice that phones don't need antivirus depends on that.
  3. On a computer, type the developer's web address yourself rather than clicking an advert, as the FTC advises. Google says that if a pop-up about a program update or download seems suspicious, go to the program's official website instead.

What should I check before installing one?

The NCSC's questions make a short checklist:

  1. Do you need third-party software at all?
  2. How will it get updates, including new signatures? The FTC says to update security software regularly or set it to update automatically.
  3. Will it be the only one? The NCSC doesn't recommend more than one antivirus product on any device. It says the benefit is minimal and the products may conflict.

For comparisons, the FTC suggests looking for recommendations from independent review sites. When you first install or switch on an antivirus product, the NCSC says to run a full scan.

What if I installed a fake or paid for one?

  1. If you gave a username and password to someone posing as tech support, change it right away, the FTC says.
  2. The FTC also says to stop logging in to online accounts on an infected computer, change your passwords and turn on two-factor authentication.
  3. Cancel any subscription before you delete the app. Apple and Google both say that deleting or uninstalling an app doesn't cancel its subscription.

There's more on messages that pretend to be security alerts in security update scam emails.

Where Failshot fits

Your password is the first layer. Failshot is the second: second layer device security, for the moment someone sits down at your Mac and unlocks it.

  • While it's on, Failshot photographs whoever unlocks your Mac, then, with Pro, records a 5-second video.
  • With the Mac's built-in camera, the green light comes on, and Failshot's window tells whoever unlocked the Mac that the unlock was photographed.
  • With Pro, turn on alerts and Failshot emails you about an unlock you don't confirm as yours, a wrong Failshot PIN or answer, or its camera access being switched off while it's on.
  • Switching it off, or quitting it from its menu, takes Touch ID or your Failshot PIN and answer, never your Mac password.

Get Failshot for Mac (macOS 14 or later) from failshot.app. Free to download. It's free to use. Pro adds video, email alerts and the encrypted vault, and you can try Pro free for 7 days. Your card is taken at sign-up and charged on day 8 unless you cancel. iPhone, Android and Windows versions are coming soon.

More questions

Is free antivirus as good as paid?

We don't rank products, because we haven't tested them. The NCSC says there are paid and free products, and some have extra features you may find useful. Its advice is to work out which meets your needs, and to run only one.

What is the best free security software?

For many people, the protection already in the operating system. The NCSC says Windows, macOS and Android include built-in antivirus by default, which will meet the needs of many organisations. Check it's switched on before adding anything.

Is free internet security worth installing on a phone?

The NCSC says you don't need antivirus on a smartphone or tablet, provided you only install apps from official stores such as Google Play and the Apple App Store, and set the phone and its apps to update automatically.

Can a website scan my computer for viruses?

Treat that offer with suspicion. CISA warns that browser pop-ups may disguise themselves as antivirus software, and Apple says not to believe pop-ups warning of viruses on your device. Close the tab.

Should I uninstall the trial antivirus that came with my laptop?

The NCSC says separate antivirus products won't always work alongside the built-in antivirus and could even stop it working. When a trial ends, you'll have to pay or register to keep using it, so decide which one you want to rely on.

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