The feds call them ATP 45, a hacker collective so dangerous that the FBI put a bounty on the group’s mastermind for $10 million. This cybercrime cell belongs to the Reconnaissance General Bureau, North Korea’s answer to the CIA, and it’s out to steal classified files. Only recently has the FBI released details about this group’s data heists, targeting US military installations, defense companies and even NASA. The World’s Patrick Winn has the inside story of investigators trying to stop these hackers — and North Korea’s infiltration of Fortune 500 companies.