Some 21 per cent of UK computer users have been hit by cold call scammers posing as computer security engineers who try to extort cash from them to fix problems which aren't there, according to the latest research from Microsoft.
The firm interviewed 7,000 users across several regions including the UK, US and Ireland, and found that such phone scams remain a popular and successful money-making technique.
Of the 15 per cent overall in the survey that said they had received a call, nearly a quarter were tricked into following the scammer's instructions, with 79 per cent suffering some kind of financial loss.
Typically, the callers pretend to be software engineers warning of a security issue on the victim's PC. They then promise to provide a free security check, in some cases convincing the user to allow them to remotely access their machine.
Across the countries surveyed, the average amount of money stolen was £543 with the average cost of repairing resulting damage caused to computers topping £1,000.
In many ways, the scammers are doing in the physical world what many scareware campaigns aim to do in cyber space; trick the user into believing their machine is infected when it is not, and then extort money to fix the non-existent problem.
Microsoft UK's chief security advisor, Stuart Aston, advised users to observe good internet security practice and be wary of unsolicited calls.
"Use up to date versions of Windows and application software, make sure you install security updates regularly and make sure your firewall is turned on and that you have antivirus software installed and up to date," he said.
"Specifically to protect against phone scams, always be suspicious of unsolicited calls or emails from people offering help with a security problem, or any other problem with your computer - even if they claim to represent a legitimate company and no matter how reassuring they sound."
In March, banking security software vendor Trusteer warned computer users to be on their guard after reporting that its customers had been cold called by similar scammers.
Most V3.co.uk readers believe that such scammers should be given harsher jail sentences to act as a deterrent.
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