What a lot of people don't know, is that a range of classified documents from the NSA have not been attributed to Edward Snowden, which means that there was at least one other leaker inside the NSA.
Initially, this leaker was called the "second source", and although he was responsible for significant leaks, they got little attention in the US. More media coverage gained the release, since 2016, of NSA hacking tools by the mysterious "Shadow Brokers".
Now, a close look at documents published by the German magazine Der Spiegel in December 2013 provided new indications that the second source could be identical with the Shadow Brokers.
http://electrospaces.blogspot.com/2017/09/are-shadow-brokers-identical-with.html