Give me the report on the FBI's investigation of the DNC's servers. Oh wait, there was never such an investigation. How can such a declaration be made without even investigating the server? The CIA's assessment was based on circumstantial evidence. Don't listen to me, here's what the NYT said:
"But the declassified report contained no information about how the agencies had collected their data or had come to their conclusions. So it is bound to be attacked by skeptics and by partisans of Mr. Trump, who see the review as a political effort to impugn the legitimacy of his election. Intelligence officials have rejected that view."
http://www.nytimes.com/2017/01/06/us/politics/russia-hack-report.html?smid=tw-nytimes&smtyp=cur&_r=0
And from the report itself:
"Some of our judgments about Kremlin preferences and intent are drawn from the behavior of Kremlinloyal political figures, state media, and pro-Kremlin social media actors, all of whom the Kremlin either directly uses to convey messages or who are answerable to the Kremlin. The Russian leadership invests significant resources in both foreign and domestic propaganda and places a premium on transmitting what it views as consistent, self-reinforcing narratives regarding its desires and redlines, whether on Ukraine, Syria, or relations with the United States."
https://www.dni.gov/files/documents/ICA_2017_01.pdf
If you actually read the report, the alleged "influence" was largely based on media outreach and viewership. Check the final page for their highly technical "confidence index". There are no concrete allegations in that report, their determination is based on RT viewership numbers and pro-kremlin tweets. Step it up guys.