Report published by New York Times on 18th Jan gives detailed information about how NSA managed to breach the impregnable fortress of North Korean computers. The The New York Times article cites unnamed “officials and experts,” and states that the NSA penetrated the China-based networks and systems belonging to North Korea’s military and its cyber warfare unit and had been tracking the evolution of their capabilities starting from 2010. NSA took the help of South Korea and ‘Five Eyes’ allies to break into the North Korean systems as per the newly documented NSA leaks. The leaked documents which can be read here (PDF) state that this was a highest possible confidential operation with the docket marked as TOP SECRET / SI /TK /REL TO USA, FVEY. It is because of this operation that President Barack Obama had no hesitation in blaming North Korea for the Sony hack. President Obama had said that he had “no doubt” North Korea was responsible because the information came through “early warning radar,” the Times said. Apparently the fear of exposing the NSA dark and deep operation in North Korea kept a lid on the law enforcement agencies from blaming North Korea directly in the first instance. It was only after many deliberations and investigations that the official line of blaming North Korea was taken by the US authorities. The leaked documents however raise question of why USA did not alert the Sony officials and security team of the impending hack attack if the NSA indeed had footprints in the North Korean computer networks. The Sony-North Korea war of words had began as early as June last year when North Korea had warned Sony that release of its movie “The Interview” would be seen as a act of war by them. “The speed and certainty with which the United States made its determinations about North Korea told you that something was different here — that they had some kind of inside view,” James A. Lewis, a cyberwarfare expert at the Center for Strategic and International Studies in Washington, told the Times. “Attributing where attacks come from is incredibly difficult and slow.” The US government or the NSA has not yet officially confirmed the leaks or commented about it.