Vocus has confirmed that a PABX systems of one of its customers was compromised and used in an attempt at international toll fraud that flooded the Triple Zero emergency service.
“At 8.30am Saturday, Vocus was made aware of unusual inbound VoIP call activity to 000 call centres between 6.09am and 7.55am that morning,” the network operator said in a statement.
“Pre-defined fraud filters meant that algorithmically generated attempts to dial international numbers failed and the attempt was aborted,” Vocus said. “However, many of these calls included a ‘000’ prefix which were routed to emergency services.”
The Sydney Morning Herald was the first outlet to report details of the incident.
On three separate occasions on 26 May, some 600 ‘blank’ calls were made to the Triple Zero emergency line. There were two bursts within 60 seconds and one period across 35 minutes according to Telstra, which operates the service.
The calls appeared to originate from multiple numbers. Operators redirected them to a recorded service that asks a caller to press ’55’ on their phone.
Vocus said that it had taken steps to prevent a repeat of the incident.
Vocus added: “Toll fraud is a significant problem and can be complex and time consuming to resolve. Vocus takes fraud awareness very seriously and works closely with customers to assist them to keep their business safe from toll fraud attacks.”
“Services connected to another Australian telecommunications provider generated unusual inbound call activity to our 000 call centres between 6am and 8am Saturday,” a Telstra spokesperson told Computerworld.
“We have worked with the government, emergency service providers and the provider to resolve the issue.
“In some cases, repeat calls were directed to police in the state in which they were determined to have originated. There was some impact on call response times during these call bursts and our network otherwise operated normally.”
Telstra informed the Australian Communications and Media Authority of the incident.
A significant Triple Zero outage earlier in May is currently the subject of government scrutiny.