Something wasn’t right about the phone screen. It had gone dark. That’s when Nick Harvey examined it more closely. It looked odd. And it was then that he saw the message. His smart phone had, in effect, been hijacked and he was being asked to pay a ransom. ‘My device had been locked’, he told BBC Radio 4’s PM Programme. He was being instructed ‘to send some money via a voucher code to get the phone unlocked’.

Ken Main knows how Nick felt. It happened to him with the computers at his hairdressing salon in Glasgow. ‘It was a pale blue screen with the message right in the middle,’ he explained. ‘If we wanted the information back we would have to pay a ransom.’

They had both become victims of what is known as ransomware - a type of computer virus which unlocks the users out of their computers or phones and demands money for the return of the files. ‘It’s like somebody breaking into your house’, Ken said.’ It was a message which kind of created the same sort of emotional fear and then you start thinking ‘God, what happens if I can’t get this information back?’‘

You are probably now trying to guess how much Ken and Nick were being asked to pay. It is possibly quite a lot lower than you would think. ‘They asked me for $50 or €50’ Nick recalled. For Ken it was slightly more.

‘They were looking for a ransom of $350 initially,’ he said. ‘When we contacted them by email, they put that up to €1000.’

The demands are set at what is regarded as a payable level, according to Jornt van der Wiel from the security software company, Kaspersky Lab. They tend to be for ‘the amount of money that people are still willing to pay in order to get their files back.’ He explained, for a small business, ‘Sometimes it’s cheaper for the company just to pay the ransom than to put back the backup because that in the end costs more’.

Nick Harvey did not have to part with any money. He managed to get his phone working again although he did lose some data. Ken, however, felt he had no choice but to pay up. ‘I said, ‘Well I need that bloody information back. I’ve got a business to run here.’ I think any businessman in my position would say ‘Yes! Let’s do it’, because I’ve got no other way of getting information to rebuild that database.’

According to Mr van der Wiel, ransomware can enter your computer via malicious email attachments. His advice is not to open any file which you are suspicious about. He says there can also be a problem if the latest ‘security patches’ on your internet browser have not been installed.