More and more businesses are falling victim to Dial Through Fraud, a kidnapping of a business phone line for making illegal calls.
If you run a weekday business, why does your itemised phone bill list calls made at the weekend? More and more business owners are asking themselves this disturbing question. The answer is Dial Through Fraud (DTF), which costs UK businesses more than £1 billion per year.
What is Dial Through Fraud?
DTF occurs when a hacker dials into a business’s PBX voicemail system, enters a decoding program, and hijacks the outbound line. The hacker can then use that line (or rent it to others) to make premium-rate or international calls. Nights, weekends and holidays are the hacker’s favourite feeding time, because those are the times the line is unoccupied and unmonitored.
The leading UK telecoms fraud watchdog says that the economic downturn has brought about a sharp rise in DTF, and most companies are either unaware of it or are poorly equipped to combat it.
Who is at risk for DTF?
Small businesses are the most frequent victims of DTF thanks to a combination of circumstances that make them especially vulnerable to attack:
- They often have a single outbound line connected to multiple inbound lines
- They rarely have in-house IT staff capable of recognising the warning signs of DTF
- They are less likely to have established security procedures or software in place
How can businesses prevent DTF?
Your phone system provider can offer options to help your business protect against Dial Through Fraud. Keep the following points in mind when you discuss the matter with your supplier:
- Limit remote access to your business’s internal phone system as much as possible
- Change PIN codes used to gain remote access frequently
- Bar voicemail ports from your outbound access trunk line
- Install a PBX firewall and intrusion detection software on your network
- Restrict overseas and night-time or weekend outbound calls
- Set up a daily call billing limit
- Review your system’s security and configuration settings regularly
- Monitor your phone traffic levels
- Read your bill carefully each month!
The Telecommunications UK Fraud Forum offers a case study and checklist with tips for securing your business phone system against DTF. They also suggest a useful rule of thumb: if in doubt, always seek professional advice.