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How scammers can take over your computer

This advice applies to England

Scams are schemes to con you out of your money. They can arrive by post, phone call, text message, email, or a scammer may turn up at your home.

Computer hackers use computer viruses to gain access to your computer details, to steal your money and identity, then scam you.  They may also get into your wireless (Wi-Fi) network for the same reason.

Fake emails and websites can trick you into buying something bogus or handing over personal details. For example websites that appear to sell event tickets. You pay for the tickets but they never arrive.

This page tells you more about ways fraudsters can get into your computer to steal your money, personal information or identity and what you can do to protect yourself.

Ways your computer can be taken over

Computer viruses

Computer viruses are small computer programs that are designed to try and infect other computers, tablets and smartphones. They break into your computer and spread from one device to the next as you communicate with other people. They are also known as malware.

How computer viruses spread

Viruses can spread through:

  • computer programs or files that appear to be harmless but actually do damage. These are called trojan viruses. For example, you may download a file with a harmless looking picture of a celebrity, which is actually hiding the virus
  • email attachments. The virus then finds new people in your email address book to attack
  • programs you download from websites
  • documents. These are known as macro viruses
  • the internet. This is known as a worm. The worm scans for other computers that are vulnerable to attack and sends a copy of itself across networks. A worm can eat up memory or network bandwidth, which will make your computer slow down or stop responding.

What viruses can do when they reach your computer

Viruses can leave unwanted software on your computer that:

  • secretly monitors your computer activity
  • scans for private information, such as passwords
  • gives scammers control of your computer
  • send out spam email
  • display unwanted advertising
  • hijack your web browser
  • use your computer to host illegal websites to con other people.  

They can also switch off your computer’s security defences, leaving it vulnerable to more viruses. And they can track what information you put into your computer by monitoring your keyboard strokes.


Spyware can track users through advertising that might pop up on your computer. When you click on the advertising link you may be taken to a website which can install a virus onto your computer without you realising it.

The virus can take over your web browser, scan your computer for private information and slow down your computer. It can be difficult to remove spyware.

Wi-fi eavesdropping

If you use a wireless network to access the internet, the signal that lets you connect to the internet uses a radio link with a range of several hundred feet. This is called a Wi-Fi network. If your network isn’t secure, other people can also access your internet link if they are within range.

Scammers can also set up access to fake Wi-Fi networks in public places. If you log onto the network, they can try to capture personal details, such as passwords and credit card information.

Other computer scams


Ransomware copies personal files or photos from your computer. When a scammer has control of them, they send a demand for money in return for the files or photos. If you don’t hand over the money, they threaten you with the release of images and files to others, to embarrass you.


Scareware is rogue security software, such as antivirus software, that protects your computer. It hides in pop up adverts or alerts that advertise security software updates.

If you click on the adverts or alerts, thinking you are downloading legitimate security software, you may inadvertently start to download scareware onto your computer.

When the scareware is installed it may fail to report viruses or say you have a virus when your computer is clean. Sometimes it will download a virus or spyware onto your computer, which steals your personal information or slows down your computer. You may also be asked to pay for these fake updates.

Phone calls pretending to be from computer companies

Callers pretend to be employees of well-known computer companies who have discovered problems or viruses on your computer. They persuade you to give them access to your computer with passwords and security information and then ask for payment and bank details.

Genuine computer companies will never do this. If you need technical help, always call or email your internet service provider's support line or talk to a computer repair company locally.

Next steps

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