Western Australia Police has warned businesses in the state to upgrade their Voice over Internet Protocol (VoIP) exchange networks after three Perth companies were hit with phone hacking call charges of $70,000.
Phone hacking, also known as phone phreaking, allows hackers to access the VoIP business exchange networks.
Technology Crime Investigation Unit senior constable, Paul Litherland, said the attacks occurred in April and took place over a weekend to maximise the breach time.
"International criminals will scan business phone systems around the world to identify vulnerabilities, which will make them easier to access," he said in a statement.
"Once access is gained, criminals will log thousands of calls to premium numbers, which in many cases they own, making huge profits."
Senior constable Litherland also said many businesses had only the basic security in place, such as default access pins or passwords, and were "easy pickings" for criminals.
"We advise businesses to change passwords, place caps on the number of calls that can be made over any given period and bar calls to international locations the company does not contact," he said.
"Businesses will often focus their attention on local internet security to avoid staff visiting unauthorised websites and for the protection of data loss, but will often overlook the strong need for protection of their telecommunications network from external attack."
Litherland also said that as the criminals were based overseas, Western Australia Police found it difficult to identify or prosecute the persons.
In December 2010, criminals targetted networks in the UK, South Africa and Romania during a similar attack that logged over 11 million minutes of calls.
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