His random act of heroism makes security researcher Marcus Hutchins famous overnight. Being celebrated by media around the world, he spends a week in Las Vegas. When he wants to leave, the FBI arrests him. They suspect him of creating malware.

From the Web:

FBI arrest of Marcus Hutchins (@MalwareTechBlog) has chilling effect

Bad news for WannaCry slayer Marcus Hutchins

What Happens When a Hacker Hero is Arrested by the FBI? | Freethink Coded