"It’s certainly possible that an NSA hacker goofed massively and left files in the wrong place at the wrong time. Human error can never be ruled out. Russian cybersleuths carefully watch for possible NSA operations online—just as we look for theirs—and even a single slip-up with Top Secret hacking tools could invite a disastrous compromise.
However, it’s far more likely that this information was stolen by an insider. There’s something fishy about the official story here. It’s far-fetched to think a small group of unknown hackers could infiltrate NSA. Furthermore, explained a former agency scientist, the set-up implied in the account given by The Shadow Brokers makes little sense: “No one puts their exploits on a [command-and-control]
server…That’s not a thing.” In other words, there was no “hack” here at all.
It’s much more plausible that NSA has a Kremlin mole (or moles) lurking in its ranks who stole this information and passed it to Russian intelligence for later use. This isn’t surprising, since NSA has known since at least 2010 of one or more Russian moles in its ranks and agency counterintelligence has yet to expose them."