The malware, using a technique purportedly stolen from the US National Security Agency, stopped care Friday at hospitals across the United Kingdom, affected Russia's Ministry of Interior and infected company computer systems in countries from Eastern Europe to the US and Asia.
The government has listed only three Australians companies among the victims of the "WannaCry" attack, but says the number is likely to rise as companies return to work today.
Riverbank IT Management managing director Malcolm Newdick said: "Last week's ransomware attack was the most risky malware attack we have seen".
"We are running around 200 global operations against cyber crime each year but we've never seen anything like this", he added.
The police said further information was available via the National Cyber Security Centre and appealed to anyone who believes they may be victims of cyber-attack to contact them.
First, the concept of ransomware: Ransomware uses a typical ransom situation, except this is like a virus* that will block your access to files until you pay the person who unleashed it on your computer. In March, Microsoft patched the vulnerability that the ransomware exploits - but only for newer Windows systems.
Wanna Decryptor, WannaCry and wcry are the specific type of ransomware program that was used on Friday's cyber attack on the NHS in Britain and Telefocina in Spain, amongst several other companies.
NHS Digital, Britain's national hospital cybersecurity overseer, stated that 16 NHS organizations across Britain had reported an incident, but that the attack did not appear to be specifically targeting NHS hospitals.
Security experts said a second wave of the attack could affect employees across the globe again, starting Monday and even spilling into the rest of the week. The interior ministry said on its website about 1,000 computers had been infected but it its cyber-security systems had localized and neutralized the virus.
Wainwright told ITV that the world faced an escalating threat, and there was concern about the level of potential attacks on Monday morning.
However there was disruption to the x-ray service.
A spokeswoman for NHS Grampian said: "Our IT teams have been working over the weekend in the affected GP surgeries".
The virus took control of users' files, demanding payments. The scope of this ransomware attack, however, is unprecedented.