The British cyber-security researcher who stalled WannaCry cyber-attack that hit the NHS has been arrested and charged in a US cyber-crime case. Marcus Hutchins, 23, has been accused of involvement with Kronos – a separate piece of malware used to steal banking logins from victims' computers. <br/><br/>Fellow cyber-security researchers have expressed surprise at the indictment. The UK's National Cyber Security Centre has said that it is aware of the situation. WannaCry spread rapidly through computer systems around the world, in an unprecedented outbreak that began on 12th May this year.