• You may already know for sure because your antivirus product is telling you it has found an infection.
• If you suspect an infection but aren't sure, the easiest way to confirm an infection on a PC or laptop is to run an antivirus scan and see if it detects anything.
  
• If you don't have antivirus, signs of infection include:
   
  • Your device is running slowly, rebooting by itself, frequently closing programs or apps you are using, or opening those you are not.
  • You have pop-up boxes from programs or apps that you don't recognise, asking you to do unexpected things.
  • Someone you know has received unexpected emails from you, advertising unlikely products, or perhaps asking for money

On a phone or tablet

• Antivirus products don't work in the same way as PCs and laptops. The safest solution is to do a factory reset – you can usually find this option in 'settings'.  
  
• If this doesn't fix the problem, you'll need expert help.

On a PC or laptop

• Update your device and programs.
  
• Open your antivirus product and run a scan, then take the actions it recommends.
  
• If your antivirus can’t clean up your device, you’ll have to wipe it entirely and reinstall everything, starting with your operating system. You may need expert help to do this.
  
• If you can't download and install an antivirus product because your web browser (such as Chrome, Edge, Firefox) is infected, you will probably need to get expert help.

Restore your backed-up data from the 'last known' good backup. You will lose any data that wasn't backed up, but trying to rescue data while your device is still infected runs the risk of carrying the infection through after wiping and reinstalling.

• Follow our advice for setting up your devices securely and keeping them safe
• Keep your device and programs and apps up to date
• Back up your data
• Check your device is encrypted
• For PCs and laptops, make sure you have antivirus and that you install security updates as soon as they are available, ideally by setting them to install automatically