National security/ Remote control of opponent cyberspace

Four years before North Korea hacked into Sony Pictures Entertainment's servers and published private information, the United States began cracking into North Korean computer networks and tracking the movements of its government hackers, the New York Times reported Monday.

The information collected through the classified National Security Agency program helped U.S. intelligence officials assess North Korea's involvement in the cyberattack and ultimately led President Barack Obama to directly blame North Korea for the attack, according to a Times report that cited current and former U.S. and foreign officials with knowledge of the program.

Starting in 2010, the NSA broke into Chinese networks connecting North Korea to the World Wide Web and embedded malware into the networks used by North Korea's cyberspies, including those working in the Bureau 121 unit believed to be responsible for the Sony hack.

NSA hacking since 2010 led U.S. to blame  North Korea for Sony attack