In the wee hours of June 14, the Washington Post revealed that “Russian government hackers” had penetrated the computer network of the Democratic National Committee. Foreign spies, the Post claimed, had gained access to the DNC’s entire database of opposition research on the presumptive Republican nominee, Donald Trump, just weeks before the Republican Convention. Hillary Clinton said the attack was “troubling.”
That's an excellent article from Motherboard (and has a few funky things, e.g. "one dumped document was modified using Russian language settings, by a user named “Феликс Эдмундович,”" :))) )