Telephone conmen cash in on Microsoft brand name TELEPHONE scammers who are pretending to be IT support staff from the computer giant Microsoft are preying on thousands of Britons and leaving them out of pocket, a new consumer watchdog investigation shows today. The cold calls made by the hi-tech conmen warn homeowners of problems with their PC, which could involve virus infections and impending system crashes. However, the phone callers recommend that the owners of the computers take out a protection plan or annual support contract that can run into hundreds of pounds. The investigation by the magazine Which? Computing says that the scale of the scam is staggering. According to figures from Microsoft itself, one in five people surveyed in the United Kingdom has received one of these scam phone calls since 2010. More than half of the victims of the telephone scam suffered problems with their computer after following the caller's instructions and 18 per cent experienced fraudulent use of their credit cards. According to Microsoft, half of the victims of the scam were aged 55 or over, and the average amount lost has been a painful £745. Which? Computing says that the scam callers prey on customers" implicit trust of the Microsoft brand name and on the vulnerability of those computer users that may lack confidence when using technology. "But make no mistake - these callers have nothing whatsoever to do with Microsoft," said Which? Computing. And they are not calling because they are concerned about the performance of your PC, either - they are just after your money. The magazine says that given that its own name has been used to lure in unsuspecting victims, it is no surprise to find that US technology giant Microsoft is damning of the scam. "It's a dreadful crime," says Stuart Aston, Microsoft's chief security adviser. It targets vulnerable, often elderly, people and it can cost them a large amount of money. As well as being a huge loss for the individual victim, thousands of successful scams can reap a small fortune for the criminals behind them, he said. Matthew Bath, editor of Which? Computing said: "If you have ever been a victim of fraud or data theft, then you will know how violated you feel. Your information - such as bank accounts and personal details - are digitally vacuumed up and used by scammers to line their pockets. "One of the most blatant is the "Microsoft IT support" phone con. Victims are phoned by a criminal pretending to be a representative from Microsoft. They will claim that there is a problem with your PC and that they can fix it for you. Give them permission and they will log on to your PC, often installing viruses, stealing data and then charging you for the privilege. And it's all lies. No reputable company will phone you up saying your PC needs fixing. They simply don't know the health of your PC. Mr Bath added that these scammers "prey on your fear that something might be wrong. It has to stop.