"The FBI, CIA and NSA all agreed that Russia was behind the hacking of the DNC..."

That's a phenomenon called "Groupthink" which these agencies are actually encouraged to avoid. It was responsible for them missing 9/11 attacks and claiming that Iraq had WMD in 2003. One would think they'd learn their lesson. Besides, whoever hacked the DNC and exposed corruption in the Clinton campaign, they did what the US media wouldn't (or didn't want to) do. If the Russian state media picked up what was true about the dirty deals at DNC, then it's not a "disinformation campaign". Quite the opposite. Disinformation is what this NYT piece is, if you want an example.