Many larger businesses use a private branch exchange (PBX) phone and/or a voicemail system. However, since 2005, PBX hacking has been a leading fraud type. Telephone hackers break into insecure PBX systems to listen to voicemail, monitor conversations or reprogram the system – all to wreak havoc on the business.
These hackers also use PBX systems to make international and long distance phone calls. When they gain access to trunk phone lines, they’ll start making a high volume of calls to international premium rate numbers that the criminals own – so they can collect revenue from those numbers.
Businesses with PBX systems may not be aware of unauthorized access or that hackers may be trying to “sell” use of the business’ telephone system to others.