Microsoft scolded the United States and other countries on Sunday for "stockpiling" software "vulnerabilities" that can cripple computers around the world after a massive ransomware attack, tied to a leaked trove of NSA spy tools, hit at least 150 countries beginning on Friday.

"The governments of the world should treat this attack as a wake-up call," said Brad Smith, Microsoft's president and chief legal officer, in a blog post Sunday.

The ransomware, known as "WannaCry," locks up computer files unless users pay a ransom in bitcoin, an online currency. Experts believe the Microsoft Windows exploit, known as "EternalBlue," was revealed as part of a NSA leak by a hacking group, the Shadow Brokers, last month. Microsoft released a patch for the exploit in March, but only for computers running an OS newer than Windows 7. After the attack, Microsoft said it had taken the "highly unusual step" of releasing a patch to protect older systems.

Of the targets hit were many hospitals in the United Kingdom's National Health Service, Russia's Interior Ministry and FedEx. At least 200,000 computers are believed to effected, BBC reported.

A U.K. security researcher, known only as "MalwareTech," who is credited with helping to limiting at least part of the ransomware attack, warned another assault may be coming "quite likely on Monday."

He explained that the latest worldwide attack is only the latest in an "emerging pattern in 2017" of problems originating in governments who are collecting vulnerabilities rather than working with technology companies to fix them.

"We have seen vulnerabilities stored by the CIA show up on WikiLeaks, and now this vulnerability stolen from the NSA has affected customers around the world," Smith said. When leaked, these exploits have caused "widespread damage," he added.

Smith compared hackers stealing this vulnerabilities from governments to the U.S. military having part of its Tomahawk missile arsenal stolen.

"[T]his most recent attack represents a completely unintended but disconcerting link between the two most serious forms of cybersecurity threats in the world today – nation-state action and organized criminal action," Smith said.

Smith called of governments to take a different approach from here on out, one similar to how they deal with "weapons in the physical world."

"We need governments to consider the damage to civilians that comes from hoarding these vulnerabilities and the use of these exploits," he said.

Smith drew attention to the call for a new "Digital Geneva Convention" in February, which would require governments to report vulnerabilities to vendors, instead of keeping them secret or selling them.

Former NSA contractor Edward Snowden, who was granted asylum in Russia since 2013 after he leaked secret information from the NSA's surveillance programs, said this is the first time Microsoft has officially confirmed this exploit was developed by the NSA.