How do you know that? Are you an FBI investigator?
Google it for more than five minutes. You can piece together the real story with a rudimentary glossing over of the facts.
How do they know it was Russia when the FBI never even get to look at the DNC's server? CrowdStrike, a private company HIRED BY THE DNC LOOKED AT IT. Red loving flag already! Not only that, but the FBI has stated multiple times that there's no evidence of any collusion. What, wikileaks releasing those emails is collusion? So the Russians hacked the DNC, gave the info to wikileaks, and wikileaks released them, which means Annoying Orange colluded with Russia? forgetin what?