The technology company Microsoft is angry with America's National Security Agency (NSA). Microsoft said the WannaCry ransomware cyber-attack happened because the NSA keeps lots of cyber-weapons on its computers. Ransomware is a type of harmful software that blocks access to a computer until the owner of the computer pays money (a ransom) to the hackers. The NSA is America's military intelligence organization. It helps to keep America's communications and information systems safe. It is also responsible for stopping cyber-attacks against the USA. However, experts say the WannaCry ransomware used computer spying tools originally designed by the NSA.
Microsoft President Brad Smith said governments needed to wake up to the problem of storing cyber-weapons that hackers can steal. He said it was as big a problem as someone stealing missiles from the USA. When talking about the WannaCry attack, he said: "This attack provides yet another example of why the stockpiling of [these things] by governments is such a problem." The European police agency Europol said WannaCry has affected 200,000 computers in 150 countries. In the UK, WannaCry caused many problems with the work of Britain's National Health Service. Many operations were cancelled. Experts warned people to back up their files because a second wave of attacks could come.