Businesses, schools, colleges and universities across South Yorkshire are being warned about a phone scam which could leave them with a hefty bill.
By using the 'dial through' fraud scam hackers target an organisation's telephone system and use it to make a high volume of calls to premium rate or overseas numbers to make a financial gain. This can leave the organisation with hefty charges.
There has been a number of cases across the UK which has prompted cybercrime specialists at South Yorkshire Police to alert organisations in the area about the scam.
Detective Inspector Steve Leach said: “Dial-through fraud occurs when hackers target an organisation’s telephone system and use it to make a high volume of calls to premium rate or overseas number, in order make a financial gain.
“Once access is gained to a telephone system, the criminals can exploit in-built services such as voicemail, call forwarding and call diversion to direct calls to a number of their choosing.”
Suspects will often take a share of the money made by the calls or will be paid for their hacking services.
Research conducted by the National Fraud Intelligence Bureau suggests that the losses involved can be high, especially when accounts are hacked during holidays and weekends, when premises are closed.
Det Insp Leach added: “Often, the fraudulent calls are not noticed until the telephone bill arrives, by which time it’s too late. If you think your system may be a target, please do all you can to safeguard against hackers.”
Police have issued the following advice on how to protect yourself against the scam:-
• Change your voicemail PIN or password if it is still set default
• Use a strong PIN or password and ensure it is changed regularly
• Disable access to your voicemail system from outside lines. Voicemail is usually used for remote workers to access.
If it is not business critical, then disable it to ensure the access is restricted to essential users and they regularly update their PIN or password
• Consider asking your telecoms provider to place a restriction on your telephone line
• Ask your provider not to permit outbound calls at times when your business is closed
• Ask your telecoms provider to alert you if there is any unusual call activity on your lines
• Review your call logs for suspect traffic
• Install a strong private branch exchange firewall and close down unused functions
• Speak to your maintenance provider or the individual responsible for your PBX* to ensure they understand the threat to correct any security risk
• Consider consulting an IT telecoms professional to ensure the settings for your PBX system are secure and the settings have been properly set up