A victim here was conned out of hundreds of pounds.
West Yorkshire Police are warning of tech-scammers who are targeting people online.
Tech-Support scammers are fraudsters who claim to offer a legitimate technical support service, often via cold calls or through pop up windows on a computer.
Action Fraud has received reports of Tech-Support scammers claiming to be from Microsoft who have conned one victim out of hundreds of pounds.
The victim fell for the scam when a pop-up window on their PC screen said their computer had been affected by WannaCry Ransomware, and provided a helpline for the victim to call.
The pop up window wouldn't close when the victim tried to shut it down so the victim rang the contact number. The fraudsters then convinced the victim didn't have sufficient antivirus protection and persuaded the victim to grant them remote access to their PC.
The fraudsters then installed a Windows Malicious Software Removal Tool - a free tool - and took £320 as payment.
Detective Inspector Benn Kemp, of West Yorkshire Police's Cyber Crime Team, said: "Cyber crime is a rapidly expanding area and takes many different forms. The reality is however, that the vast majority of cyber crime can be prevented if people are aware of certain threats and situations where you could become a victim.
"I would urge members of the public to be on their guard when surfing the web and if you come across this message on your screen, report it to Action Fraud immediately.
"More importantly, ignore the instructions within the message. Microsoft warning messages will never include a phone number and Microsoft will never reach out to you proactively to provide technical support."