Marcus Hutchins charged

NHS cyber-defender Marcus Hutchins charged in US

Marcus Hutchins, 23, has been accused of involvement with Kronos - a separate piece of malware used to steal banking logins from victims' computers.

Fellow cyber-security researchers have expressed surprise at the indictment.

The UK's National Cyber Security Centre has said that it was aware of the situation.

WannaCry spread rapidly through computer systems around the world, in an unprecedented outbreak that began on 12 May.

Shortly afterwards, Mr Hutchins was thrust into the limelight after he found a way to stop it from spreading.