The virus, known as WannaCry, infected over 20,000 computers in 150 countries.
"We will see more victims here and that's very sad always", the Prime Minister's cybersecurity adviser Alastair MacGibbon told the ABC this morning. He tweeted: "The cyber threat is not over".
"As our hospitals are still experiencing some delays and disruption, we would ask the public to use other NHS services wherever possible".
Speaking to ITV News, the Director of Europol, Rob Wainwright said: "We've seen the extent to which the ransomware, which had its infection rates slowed down over the weekend, now mutated by the cyber crime groups behind it".
He also recommends keeping security software and operating system software up to date to keep them in-line with the latest security updates. "I am anxious about how the numbers will continue to grow". "Organisations across Australia have been taking active steps to protect their networks over the weekend", the statement said.
"It started its assault against hospitals across the United Kingdom and shortly after spilled across the globe", the agency said.
Meanwhile, health authorities are racing to upgrade security software amid fears hackers could exploit the same vulnerability with a new virus.
Meanwhile, Labour and the Liberal Democrats have demanded an inquiry into the attack, though home secretary Amber Rudd told the BBC that the government had the "right plans" in place to limit the attack's impact.
"We have been concerned for some time that the healthcare sectors in many countries are particularly vulnerable".
The warning stated that a data security review revealed that there was a "lack of understanding of security issues" and breaches often occurred because staff members were working "with ineffective processes and technology."
The attack on Friday saw ambulances diverted and operations cancelled up and down the country.
The cyber attacks started Friday and spread rapidly around the globe using a security flaw in Microsoft's Windows XP operating system, an older version that is no longer given mainstream tech support by the USA giant.
It's believed that Microsoft computers have a vulnerability to the malicious cyber attack, which was reportedly identified by the National Security Agency in the USA and then leaked onto the internet.