Cyber Storm II was today officially launched by the Attorney General in which five countries will engage in an international hacking exercise.

The wargame is a follow-up to last years' Cyber Storm and will test the national security of Australia, the United States, Canada, the United Kingdom and New Zealand between March 11 to 14.

AG Robert McClelland joined UK deputy high commissioner Tim Gurney, Australian Federal Police (AFP) commissioner Mick Keelty and ambassadors from the US and Canada to launch the event in Canberra today.

"It's imperative we test our preparedness and response capabilities. This is why we have Cyber Storm II," McClelland said.

"The US defence department detects about three million unauthorized probes of its computer networks everyday.

"By playing out various real-time scenarios, we can see how we measure up and how we can improve."

Cyber Storm divides participants into attackers and defenders over simulations that test national responsiveness to cyberattacks on IT systems and transportation, communications, and chemical infrastructure.

The event is lead by the US Department of Homeland Security and supported by more than 100 public, private and international organizations including the FBI, AusCert, the AG department, the Department of Defence, the AFP, Microsoft, Verizon, McAffee and Telstra.

The first Cyberstorm event involved nine large IT firms, six electricity utility firms (generation transmission and grid operations) and two major airline carriers. The vendors involved were Cisco, Computer Associates, CSC, Microsoft, Symantec and Verisign.

Telstra corporate security and investigations director Jules Scarlett said will develop its own security infrastructure around the results of Cyber Storm II.

"Cyber Storm II is an ideal vehicle to exercise and explore potential vulnerabilities to cyber attacks in a trusted and secure information-sharing environment," Scarlett said.

"[Ensuring] our networks have the necessary protection and resilience is ongoing; preparing, planning and exercising are key to developing a robust capability to respond and recover from significant events.

"Our participation also helps us to tap into different aspects of security thinking and develop important networks with law enforcement, government and peer organizations."