About as impossible as the Snowden exfiltration, so that makes it entirely believable.
All it takes is one rogue employee or plant. And if you don't want to burn an inside asset it would pay off to release files that are several years old.
> What this have do with fun Cyber Weapons Auction? We want make sure Wealthy Elite recognizes the danger cyber weapons, this message, our auction, poses to their wealth and control. Let us spell out for Elites. Your wealth and control depends on electronic data. You see what "Equation Group" can do. You see what cryptolockers and stuxnet can do. You see free files we give for free. You see attacks on banks and SWIFT in news. Maybe there is Equation Group version of cryptolocker+stuxnet for banks and financial systems? If Equation Group lose control of cyber weapons, who else lose or find cyber weapons? If electronic data go bye bye where leave Wealthy Elites? Maybe with dumb cattle? "Do you feel in charge?"
https://web.archive.org/web/20160815152123/https://github.co...
To me it seems impossible that non-state-sponsored hackers would have gotten their hands into top secret NSA hacking tools. If I'd have guess it would seem that TheShadowBrokers are "useful idiots" that Russia gives information in the way they did (probably) with Wikileaks. The real question is why would anyone leak these files at this very moment? Did it take this long to get angry at Trump or are there some others factors at play?