Scammers are hijacking vulnerable computers following the worldwide cyber-attack.

Fraudsters are pretending to be tech-support from Microsoft to gain remote access to PCs and charge victims to install software that is free.

One victim was targeted after a pop-up window advised that they had been affected by the WannaCry Ransomware.

They then called the help number advertised and allowed the swindlers to install Windows Malicious Software Removal Tool and charged £320 to install the free programme.

Computer users are warned by Action Fraud that warning messages will never include a phone number and that Microsoft never approaches customers to provide unasked for technical support.

People are advised to never call numbers on pop-up messages, never to allow remote access to your computer and never to give out passwords or pin numbers.

Microsoft or someone on their behalf will never call you, so if you receive unsolicited calls, hang up if you are unsure of the caller’s identity.

If you believe you have been a victim, check for any additional programmes or software that may have been installed and contact your bank to stop any further payments.