Further reports have emerged about how the ransomware, which has gone on to impact users and businesses in more than 130,000 countries, became such a problem.
Microsoft announced the patches around the same time it said it still doesn't know what the precise starting point was for Friday's WCry outbreak.
Teams of technicians worked "round the clock" Saturday to restore hospital computer systems in Britain and check bank or transport services in other nations after a global cyberattack hit dozens of countries and crippled the U.K.'s health system.
Citing a written statement by BTK, Turkey's official Anadolu news agency said the cyberattack affected 74 countries, "including Turkey in a small way".
"It's an global attack and a number of countries and organisations have been affected", she said. It was leaked previous year by a group called the Shadow Brokers, and Microsoft issued a patch to fix the vulnerability.
In the US, FedEx reported its Windows computers were "experiencing interference" from malware but would not say if it had been hit by ransomware.
As you may have heard, a massive ransomware attack has infected PCs in at least 99 countries.
It was not immediately clear how many other countries were affected.
Avast said the majority of the attacks targeted Russia, Ukraine and Taiwan. The official was not authorized to be publicly named. A DDoS attack - or denial of service - is an attempt to flood a website with so much traffic that it impairs normal service. The messages include the ransom demand, $300 in bitcoin, and instructions for recovering files.
Then it adds in slightly mangled syntax: "But you have not so enough time". The hacked screen informs users that unless they pay within three days, the amount will double.
Other health-care centers, meanwhile, turned off their computers to avoid potential infiltration.
Alan Woodward, visiting professor of computing at the University of Surrey, said there was evidence the ransomware was spreading using a Microsoft flaw exposed in a recent leak of information from USA intelligence agencies. But the basic business of hospitals was being thrown into turmoil.
"A lot of people are going to go to work on Monday and click on a link in their mail - completely oblivious that all of this is going on or have heard about it and think that it's over - and suddenly wipe out their whole company", Gazeley said from Hong Kong. In February 2016, the Hollywood Presbyterian Medical Center in California said it had paid a $17,000 ransom to regain control of its computers from hackers. And while other attackers might use the same flaw, such attacks will be steadily less successful as organizations patch it.
But @MalwareTechBlog warned that the "crisis isn't over" as those behind it "can always change the code and try again".
If you have an older Vista or Windows 7 system, check out our tips on how to set up and check Windows Updates.
WannaCrypt/WannaCry ransomware has affected Windows XP systems across the globe. "In other words, Microsoft is no longer looking for and seeking to fix vulnerabilities in the system".
Nachreiner also recommended organizations invest in advanced malware protection, and build up a multi-layered defense to cyber attacks.
Most of the affected hospitals were in England, but several facilities in Scotland also reported being hit.
The UK's National Health Service fell victim, its hospitals forced to close wards and emergency rooms and turn away patients.
Joshua Douglas, chief strategy officer at Raytheon Foreground Security, told eSecurity Planet by email that by targeting networks supporting vital services like healthcare, cyber criminals are consciously putting human safety at risk for financial impact.
Andrew Clarke, EMEA director for One Identity, said: "This is an unusual move by Microsoft and serves to demonstrate the seriousness of this type of attack. The investigation is at an early stage but we believe the malware variant is Wanna Decryptor".
Writing in the British Medical Journal, he said: "We should be prepared: more hospitals will nearly certainly be shut down by ransomware this year". It's unclear whether the two cyberattacks were related. Many canceled all routine procedures and asked patients not to come to the hospital unless it was an emergency.
East and North Hertfordshire NHS Trust, which runs hospitals in an area north of London, said "the trust has experienced a major IT problem, believed to be caused by a cyberattack".
"I'm a bit of a nervous person and had to get settled about the operation, which I was". That number is likely to go up, Gazeley said. "A cyberattack? That doesn't happen every day". "It's interfering with day-to-day functioning", Hirst said.
Services in London, the central city of Nottingham, and the counties of Hertfordshire and Cumbria were affected, according to the BBC.
Cybersecurity has been high on the agenda of many high-level gatherings of Western military and political leaders.
Organizations around the world were digging out this weekend from what experts are calling one of the biggest cyberattacks ever.