A new report shows the Australian Cyber Security Centre, a government agency created to counter online threats, has responded to more than a 1,000 serious incidents affecting government systems over an 18-month period to June this year.
Dan Tehan is the Minister assisting the Prime Minister for Cyber Security.
"They are sophisticated and they can take various forms"
The 2016 Threat Report says one of the most sophisticated cyber attacks was against the Bureau of Meteorology last December.
It says suspicious activity was detected on two of the bureau's computers - with malicious software later infecting the entire network, and system passwords compromised.
Peter Jennings from the research and advocacy group, the Australian Strategic Policy Institute, says another country is suspected of being behind the attack.
"I think it is quite obvious it wasn't Canada, Costa Rica or Colombia, it was more than likely China as being the state with the most interest to undertake this type of attack"
Special advisor to the PM Alastair MacGibbon says the information gained would potentially be valuable to another country.
"It looks at earthquakes, it looks at a whole range of things vital to our economy, doesn't surprise me that a foreign nation would be interested in that type of information"
Peter Jennings from the Australian Strategic Policy Institute believes the Bureau of Meteorology was targetted because weather prediction is big business for countries looking to maximise crop yields, and deciding when to harvest.
He says the bureau is also linked to other government departments, including defence.
"It may well be that what was being looked for here was the weakest link in the govt chain so that attackers could find their way into more sensitive networks"
Another area of concern identified in the Cyber Threat report is the rise of online activity by groups deemed to be terrorist organisations.
It says such groups will be able to compromise secure Australian government networks with destructive effect within three years.
But the government says the threat of a cyber attack from terrorists is currently ranked low, even as Australia's digital integrity is being increasingly tested.