Following the recent cyberattack on Sony, the U.S. very quickly laid blame North Korea, leading many to wonder how government officials had traced the origins of the attack so quickly. A report in The New York Times claims that the National Security Agency (NSA) had already hacked into North Korea's networks before the attack occurred. The article cites a recently leaked NSA document and "officials and experts, who spoke on the condition of anonymity."
The Times says that as far back as 2010 the U.S. implanted "beacons" to serve as an "early warning radar" about attacks originating from North Korea. However, the NSA failed to spot the warning signs of the impending attack against Sony before it occurred.
North Korea reportedly has an army of 6,000 computer experts trained in cyberwarfare.