Opinion: Down to the wire

Two months later, after hours of investigation, several exasperating conversations with our telecoms provider and a circuitous excursion into the murky world of the phreaker — or telephone hacker — we were able to tell our accountant: 'We are now one of the six per cent of British businesses to have had a telephone line hacked'.

Here are the facts: in the quarter covered by that £739 bill, 144 phone calls were made on that modem line to a premium-rate 09 number, registered to a private house in Manchester.

At our end, the line is connected to an Apple Mac run by the managing director of our web design company. He is based in the office on only four days a week. When he's not here, his computer is switched off and the line is not connected to anything capable of sending a signal.

And yet calls were made on days when the line at our end was lifeless. They were also made using an auto-dialler. On 21 August, for instance, calls were made at 15:26, 15:28, 15:30, 15:32 and so on – a wearying rate even for the very committed. The 09 number is an internet site, and is password protected. When we tried to dial it, we couldn't.

An internet search quickly turned up everything we needed to know about how to become telephone hackers, including wiring diagrams for BT junction boxes, a Phreakers' Handbook — banned in Britain but available for download free – and an online catalogue of hacking kit including auto-diallers, on sale 'for research purposes'.

We also discovered that if we had been hacked we would be in very good company: Siemens Communications' website reveals that New Scotland Yard has lost £1m through telephone hacking and that a leading advertising agency has lost £60,000 to telephone fraudsters over a four-day period. We have subsequently heard of a UK bank that lost £600,000 in three weeks.

For obvious reasons, victims are usually reluctant to publicise their losses – Siemens' claim that six per cent of British businesses have been hacked may well be an underestimate. Telecoms industry body the Forum of Irregular Network Access suggested in March this year that worldwide telephone fraud is costing $55bn (£39bn).

There are different types of scam. Some of them are extremely simple: a message sent to pagers asking users to dial an 09 number without letting them know that calls are being charged at premium rate; phones manufactured in Eastern Europe that have auto-diallers built into them. Others are much more sophisticated, such as the hacking of computerised PABX systems.

'It's a very profitable business because you don't need any customers,' says David Pullen of Manchester-based telecoms security consultancy Fraud Management. 'You don't need anybody on either end of the line to generate money.'

That is why organised crime has become involved in telephone hacking, he said.

We won't go into the details of the scam from which we believe we suffered - it would be too easy to emulate – but Pullen says it is quite common. And if the hackers move on before you get your inflated bill, the crime is virtually untraceable.

Despite our investigations, and an official complaint to OFTEL, we ended up paying the bill. After tests – surprise, surprise – it was found that our line was clean. In those circumstances, responsibility for covering the cost rests with the customer. And if you don't pay, you get cut off.

The one bright spot in this story is that we did trace the 09 number and speak to the guy at the other end. Within two minutes of mentioning the words 'telephone hacking', he offered to pay half the bill. We're still trying to work out why.