Police warn businesses of telephone Scam

editorial image

Lincolnshire Police are passing advice on to businesses in the area to prevent themselves becoming victims of a national rise in fraud committed through the use of ‘in house’ telephone systems.

The National Fraud Intelligence Bureau has identified an increase in the criminal use of ‘PBX fraud’ impacting upon businesses.

This fraud is committed through the use of Private Branch Exchanges (PBX) which are telephone systems that enable organisations to improve communication both internally and externally.

PBX/dial-through fraud occurs when hackers target these systems from the outside and use them to make a high volume of calls to premium rate or overseas numbers to generate a financial return.

How does it work?

This type of crime can take one of two forms:

- Criminals use auto-diallers to identify systems which are easy to hack into, especially voicemail.

- The system is subject to a sustained cyber attack to establish the pass code that will give them access to the PBX system itself.

This can be relatively straightforward as often businesses leave the password/code on default settings.

Once access is gained, the criminals can exploit in-built services such as message forwarding and call diversion and can make calls on the organisations account.

The criminal can make their money in two ways:

- Dialling premium rate numbers to which they are affiliated

- Dialling international numbers through the compromised telephone system, especially to Eastern Europe, Cuba and Africa.

Who is affected?

The victims are often small to medium-sized businesses, but schools, charities and medical/dental practices could also be affected, with losses sometimes up to tens of thousands of pounds.

This type of fraud is most likely to occur when organisations are most vulnerable i.e. during times when businesses are closed but their telephone systems are not, for example in the early hours of the morning or over a weekend or public holiday.

DS JARMAN of the Economic Crime Unit, reinforces a number of steps that can be taken which will significantly reduce the risk of victimisation:

- Use strong pin/passwords for your voicemail system, ensuring they are changed regularly.

- If you still have your voicemail on a default pin/password change it immediately.

- Disable access to your voice mail system from outside lines. If this is business critical ensure the access is restricted to essential users and they regularly update their pin/passwords

- If you do not need to call international numbers/premium rate numbers, ask your telecoms provider to place a restriction on your telephone line.

- Consider asking your network provider to not permit outbound calls at certain times e.g. when your business is closed

- Ensure you regularly review available call logging and call reporting options.

- Regularly monitor for increased or suspect call traffic.

- Secure your exchange and communications system, use a strong PBX firewall and if you don’t need the function, close it down.

- Speak to your maintenance provider to understand the threats and ask them to correct any identified security defects

If you have been a victim of fraud, contact Action Fraud at www.actionfraud.police.uk or 0300 123 2040 or the police.