A relatively small group of hackers could carry out a cataclysmic cyber terrorist attack, similar in scale to the 9/11 atrocities, consultancy firm Deloitte Australia has warned.
But the world - and Australia in particular - may be reasonably well prepared to deal with the fall-out.
Deloitte Australia lead technology risk partner Dean Kingsley pointed to recent flaws found within software programs that remotely control air conditioning, heating and elevators in large office towers as one weakness cyber terrorists could exploit.
Hackers did in fact infiltrate an internet-connected heating system at a New Jersey-based firm in December, according to an FBI memo.
'I think those are very worrying developments and I think that's a real wake-up call for technology companies that are in the business of creating generic control systems,' Mr Kingsley said.
'Because those are things that can directly impact life safety, those things that if compromised could be the digital 9/11.'
US Homeland Security Secretary Janet Napolitano warned in late January that a 'cyber 9/11' attack could happen imminently, targeting critical US infrastructure such as water, electricity and gas lines.
Mr Kingsley said a major cyber terrorist attack could be executed by a relatively small number of people with specialised knowledge.
'In the same way that what happened in 9/11 was fundamentally an asymmetric terrorist threat of a physical sort,' he added.
'That capability, in a digital world where our lives are controlled by digital devices, that is definitely a change in the threat profile.'
But he said the infamous September 11, 2001 attacks on New York's Twin Towers meant governments and organisations are now far better prepared for terrorism attacks and he 'remained confident' that a 'digital 9/11' can be averted.
'I think we're talking much more openly about these issues today in the digital realm than we ever spoke about them in the physical realm,' he added.
'I don't remember anyone ever publicly talking about the idea of flying a plane into a large building.
'Security agencies may well have been speaking about it, but it wasn't in the public consciousness in the way these digital threats are.'
Deloitte believes Australia is well prepared to guard against digital attacks and pointed to plans announced by Prime Minister Julia Gillard in January to ramp up the nation's cyber security.
'We actually believe Australia is getting to be ahead of the game in that respect,' Deloitte security and resilience lead partner Tommy Viljoen said.