Foreign Hackers Take Down Triple Zero Network

By Cameron Abbott and Georgia Mills

The triple zero emergency call service, operated by Telstra, was subjected to an onslaught of more than 1000 offshore calls on Saturday morning, leading to a number of genuine emergency calls being unanswered and sparking a government investigation.

It is uncertain exactly where the calls originated, but telecommunications company Vocus confirmed that the calls originated from one of its customer’s phone exchange systems being compromised.  The calls were an attempt to commit international toll fraud, where a hacker fraudulently gains access to a phone system to make international calls.  Vocus reportedly said its fraud filters meant algorithmically generated attempts to call international numbers usually failed, but a number of attempted calls containing a 000 pre-fix routed to Australian emergency services. The telco is taking steps to prevent another such occurrence.

During the incident, triple zero calls were answered by operators and directed to a recorded service asking them to press ’55’ to ensure the calls were genuine.  Questions have been raised about Telstra’s handling of the situation, which left some Australians waiting for up to 9 hours for a call back.  A Telstra spokesman said the telco worked with the government, emergency services and Vocus to resolve the issue, in some cases redirecting repeat calls to police in the state the call originated in.

While the hackers did not intend to have this effect, the outage reveals how a relatively unsophisticated attack can wreak havoc on our emergency call service.  It all usefully highlights how one organisations vulnerability and can be turned into a means of further disruption.  We are left wondering how such a simple event such as high volumes of automated calls wasn’t well and truly protected against already.  Moves to challenge key infrastructure owners to improve their security cannot come soon enough.