A cyber security threat was reported to the national watchdog once every eight minutes in the past financial year, with large numbers of cybercrimes driven by the pandemic.
The Australian Cyber Security Centre's latest Annual Cyber Threat Report revealed more than 67,500 cybercrimes were reported in the 2020-21 financial year, an increase of 13 per cent from the year before.
Losses from cybercrimes totalled more than $33 billion during the 12-month period.
The report found cyber criminals exploited the COVID situation in Australia, with more than 18,000 cybercrimes related to the pandemic.
About one-quarter of all cyber security incidents affected critical infrastructure such as health, education and transport, while 35 per cent of incidents affected governments at all three levels.
The centre said ransomware remained one of the most serious types of cyber threat, which increased by almost 15 per cent in the past financial year.
In one incident, a ransomware attack at a major Melbourne health network in March this year forced some elective surgeries to be postponed.
The report said a large number of the cyber attacks were carried out either by state-based actors or by criminals.
"No sector of the Australian economy was immune from the impacts of cyber crime and other malicious activity," the report said.
"Government agencies at all levels, large organisations, critical infrastructure providers, small to medium enterprises, families and individuals were all targeted over the reporting period."
The compromising of business emails resulted in the average loss of more than $50,600 per business, more than one-and-a-half times higher than the previous financial year.
While a large number of cyber attacks targeted Australians during the early stages of the pandemic with more people working from home or connecting with family and friends virtually, it's expected COVID-related cyber threats will continue as restrictions and lockdowns ease.
Assistant Defence Minister Andrew Hastie said increased cyber security measures were needed to help combat the rise in cyber attacks.
"Malicious cyber criminals are escalating their attacks on Australians," he said.
"We need all Australians to be vigilant by taking simple cyber security steps including using strong passphrases, enabling two-factor authentication, updating software and devices and maintaining regular data backups."
Australian Associated Press