I don’t think it was a hack at all. I think it was a leak by someone in the DNC who thought that Bernie deserved fairer treatment than he was getting. Thus the payback.
I think pissed off FBI agents are behind it.
GREGORY: "... I mean, he is encouraging Russia which, by all accounts, was behind a leak of our major -- uh, one of our major political parties -- uh, to do more, to go beyond, to try to hack into, uh, Hillary Clinton's server to find missing emails,...
Tongue-in-Cheek Trump Comment on Russia Causes Total Media Meltdown