Users of call minder services should take precautions and
increase security, a Dunedin communications consultant has
The warning comes after phone lines at an Otago business were
hacked and more than $100,000 worth of international calls
Black Rock Consulting Ltd director Steve Cogger said a client
had two call minder services hacked and calls were forwarded
to international numbers.
The calls, which totalled about $110,000, were made within a
period of 48-72 hours.
The hacking began minutes after the close of business on
Friday, December 20.
Hackers had commonly targeted private automated branch
exchange networks (PABX), such as intra-company telephone
networks, he said.
But this was the first time Mr Cogger had seen call minder
''Anyone with a call minder is vulnerable,'' he said.
Although it was a relatively new method of fraud, it had the
potential to become more common if security measures
protecting call minder services were not robust, Mr Cogger
''People should be proactive in ensuring they have a pin
number of a minimum of six digits and change it regularly.''
If people noticed irregular calling activity and unexpected
costs on their phone bill, they should immediately contact
their provider, he said.
Vodafone head of fraud and security Rhys Metcalfe said the
method used to hack call minder services was no different
from that used to hack PABX networks.
''Any type of call forwarding service ... that is secured by
a pin can be a target, from a small business with one line to
a large business with a PABX and multiple lines,'' he said.
''By hacking into voicemail, offenders can set up call
forwarding to make large volumes of international calls to
high-cost destinations in a very short space of time,'' Mr
During the past few months, there had been a ''substantial
increase in fraud across telecommunications providers in New
Zealand'', he said.
''Until recently, hackers focused on European markets, but
changes in regulation over there to combat fraud have
effectively encouraged hackers to Australasia.
''New Zealand and Australian telcos are co-operating in an
effort to combat this type of fraud.''
Telecom communications manager Julie Wagener said the use of
call minder services by hackers was ''certainly not a regular
occurrence'', but ''unfortunately it does happen''.
Telecom monitored activity to keep fraud to a minimum and
would apply an international toll bar on lines where it
suspected fraud, she said.
Users were responsible ''for ensuring appropriate security
measures are in place'' and reimbursement was awarded on a
case-by-case basis, she said.
Mr Cogger said the issue highlighted the need for all users
to take phone security seriously.