There are suggestions by the CIA that Russia hacked the Democratic National Committee and John Podesta's email for the purpose of helping Trump win the election. The FBI disagrees. The CIA also apparently claims the Republican National Committee was hacked, but the Russians deliberately withheld release of any information gathered by that hack.
Reince Priebus denies the RNC was hacked, and says that after conferring with the FBI.
An alternative explanation for the hack of the DNC and Podesta is that some entity other than Russia easily found the means to get into those servers via Hillary Clinton's unprotected private server. There's more public evidence pointing to that than there is to the Russians.
Update: Dec 13 10:50AM
Top U.S. spy agency has not embraced CIA assessment on Russia hacking