What to do if you’ve had a PBX dial through fraud


What is it

Your phone system being compromised and a multitude of premium calls being put through your system.

The first time you may know this has happened is from an unusually high phone bill.

First Steps

  1. Disconnect phone system immediately,
  2. Contact telephone provider to log date and time of suspected attack so they can monitor outbound call destinations.

Who to Contact

  1. Action Fraud
  2. Call telephone provider and set up call logging on any system that is suspected to be part of fraud

Follow up action

  1. Restrict calls to destinations that should not normally be called, premium rate calls, overseas or any directory enquiry services.
  2. Set voicemail up securely on your system and disable voicemail access from outside lines.
  3. Set up secure pins for access to remote voicemail
  4. Put restrictions on any extension that must have access to outside line using voicemail

Next steps

  1. Disallow access to the administration facility of the PBX.  Configure any networked telephone exchanges to restrict support companies from calling in from outside the PBX to dial calls as if from one of the extensions
  2. Regularly change to random passwords for the administration interface
  3. Configure administration modem to only answer from a single telephone number
  4. Avoid auto features and ensure interactive voice response and auto attendant options for accessing outside lines are removed
  5. Ask telephone provider to set up monitoring and to cut off services if they exceed pre-agreed thresholds

For further advice from Get Safe Online