Revealed: how to hack into a mobile phone

HERE IS some important advice for people having illicit affairs or negotiating lucrative new jobs. Don't leave any messages on a mobile phone. And make sure no one leaves you any.

In an astonishing breach of security BT Cellnet has handed out, over the telephone, a confidential pin number allowing the recipient to listen in to the confidential messages of any of the five million customers on their network.

The Independent on Sunday has that pin number and yesterday was able to hack into the message systems of 15 people. Their permission was obtained in advance.

Having done this we contacted BT Cellnet to inform them of the breach of security. Despite repeated requests it proved impossible to speak to anyone in authority although we explained the seriousness of our request. We were told to phone back on Monday.

Our informant obtained the vital password by informing the company that she had lost her phone but was expecting an important message.

Once given the pin number all she had to do was to phone, tap in the secret code and listen to the messages. But because the code is non-specific it also enables her to retrieve the messages of everyone else on the Cellnet network. All she needs to know is their number.

This is done by calling the person's mobile phone number when the phone is switched off and then entering the magic pin number followed by two other numbers.

This violation of personal security can potentially affect all of the company's five million customers. The last security breach to affect mobile phone companies was criminals "cloning" phones to make calls for free; it cost the mobile phone companies millions of pounds. It was to tighten security that old-style analogue phones were replaced with digital phones which are supposedly hacker and criminal-proof.

But the ease with which message systems can be broken into indicates that digital phones are no more secure than the older version if staff are giving out sensitive information so easily.

The National Consumer Council said it was "astonishing" that the information was available to consumers and said it raised enormous questions about security and privacy.

"People could access all sorts of sensitive information this way," added a spokeswoman.

"Given the number of people who now have mobile phones, this really is very worrying and would make people think twice about relying on them."