According to Edward Snowden the hack of the NSA Equation Group may be a Russian response to the US. The leak is likely a warning that someone can prove U.S. responsibility for any attacks that originated from this malware server. Edward Snowden believes that hackers compromised a staging server used by the Equation group used to coordinate the attacks, it was not so difficult for the skilled Russian hackers. The Russian cyber units have a deep knowledge of NSA arsenal and are able to detect any attacks they are.”]
Source: http://securityaffairs.co/wordpress/50357/intelligence/snowden-nsa-hack.html