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Malware and computer viruses

What it is

Software that’s been made by someone so that your computer, laptop, tablet or mobile phone doesn’t work as it’s supposed to. In some cases it also collects information or data saved on your device, and passes it on.

It’s also known as viruses, worms, trojan horses, spyware, adware, scareware and crimeware.

Protect yourself

  • Make sure your computer has a firewall and reputable anti-virus software. Without these, your computer has no defence to block infections. Learn how to protect your PC or Mac.
  • Take care downloading files. If you don’t know someone who’s sent you an email with an attachment, or you’re not sure about a website offering a file to download, don’t do it out of curiosity.
  • Browse safely on the web. Get to know the risks and use the same level of caution as you would in the real world; don’t automatically trust something unfamiliar.

Spot the signs

  • You’re being offered or told to download something from a website that you haven’t visited before and doesn’t look legitimate, or from a stranger who’s sent you an email.
  • Your internet connection or the computer’s general performance suddenly becomes very slow, you can’t access files or programs, or you’re unable to log in at all.
  • There are signs other people have accessed password-protected accounts, or your bank statements shows things you’ve bought or withdrawals you can’t remember making.

How it happens

There are many different types of malware or computer viruses that do different things. A lot of infections are designed to either steal personal information you’ve stored on your computer and pass it back to the virus creator so they can steal your identity.

If you’ve saved online banking information, they could use it to log in themselves and empty your account. Alternatively they may trick you into visiting a fake banking website to steal your details.

In some cases, ransomware is designed to deny you access to your files unless you pay a fee.

Malware gets on to your computer by adding a file from somewhere like an external hard drive, or more commonly by downloading a file when you’re connected to the internet. You may not know your computer has a virus straight away; it can carry out what it’s programmed to do without any visible signs.

The virus may use spyware, which tracks your browsing history to gather information about your online shopping and banking, or keylogging, which can detect the exact letters or numbers you type on your device’s keyboard, stealing usernames and passwords as well as debit or credit card numbers.

Some malware, called scareware, poses as a genuine anti-virus software download, or will tell you to install an urgent-sounding update to keep a virus off your computer.

How to report it

Report it to us online using a different computer to the one that you think is infected, or call 0300 123 2040. Tell your bank if you think your details have been found by someone else.