According to a US Lawmaker North Korea Internet outage occurred in December could be a response for the cyber attack against the Sony Pictures Entertainment. Security experts speculated that the incident was a retaliation for the Sony hack. Republican chairman of the House Homeland Security Committee Michael McCaul confirmed that the outage of North Korean connection was the response of the US to the attack. McCaul urged the US Government to do more to protect American companies from cyber attacks. In reality there is a silent cyber war between North Korea and the US, Snowden revealed.”]
Source: https://securityaffairs.co/wordpress/35062/cyber-warfare-2/north-korea-sony-hack.html