The U.S. just blamed North Korea for the WannaCry malware attack. The cyberattack targeted more than 300,000 computers affecting hospitals, businesses and banks in 150 nations. President Trump's aide Thomas Bossert made the accusation in the Wall Street Journal. "North Korea has acted especially badly, largely unchecked, for more than a decade, and its malicious behaviour is growing more egregious. WannaCry was indiscriminately reckless." Thomas Bossert The attack caused billions of dollars of damage.