“We thank our staff, patients and their families for patience during this situation and we will keep them informed.”

Eastern Health also runs day hospitals and community health services, including Yarra Ranges Health, Yarra Valley Health, Wantirna Health and the Peter James Centre in Burwood East.

James Bergl, Asia-Pacific vice president at cybersecurity company Datto, said there had been a significant uptick in cybercrime, particularly malware, ransomware and phishing attacks, during the coronavirus pandemic.

“This latest attack on Eastern Health proves that healthcare organisations need to be on high alert this year,” he said.

“The consequences are higher for healthcare organisations that can’t risk downtime due to the critical services they provide for patients.”

Mr Bergl said cyber criminals recognised many organisations were vulnerable so it was important to practise stringent “IT hygiene”.

“Cyber hygiene, such as maintaining backups, is critical in the sector in order to combat against future crippling cyber attacks,” he said.

In August 2020 the Australian Cyber Security Centre issued new advice on mitigating ransomware threats in the healthcare and aged care sectors saying they were “a particularly lucrative target for cyber criminals due to the value and quantity of personal data held.”