There is numerous evidence of the work conducted by the internet trolls in Russia e.g. from the court cases when the previous employees of the "troll factory" have sued their employer. Facebook announced in September 2017, that it had found more than 3,000 ads addressing social and political issues that ran in the US between 2015 and 2017 and that appear to have come from accounts associated with a Russian entity known as the Internet Research Agency.
In the US, both the Congress and the FBI are investigating the alleged Russian meddling in the 2016 presidential election. Special counsel Robert Mueller investigates whether President Donald Trump’s campaign colluded with Russia during the election. Background: Reuters, Office of the Director of the National Intelligence assessment