According to The Washington Post, it did:
Two teams of independent researchers found that the Russians exploited American-made technology platforms to attack U.S. democracy at a particularly vulnerable moment, as an insurgent candidate harnessed a wide range of grievances to claim the White House. The sophistication of the Russian tactics may complicate efforts by Facebook and Google to crack down on “fake news,” as they have vowed to do after widespread complaints about the problem.
There is no way to know whether the Russian campaign proved decisive in electing Trump, but researchers portray it as part of a broadly effective strategy of sowing distrust in U.S. democracy and its leaders. The tactics included penetrating the computers of election officials in several statesand releasing troves of hacked emails that embarrassed Clinton in the final months of her campaign.
The Foreign Policy Research Institute, who took part in the research, has been tracking Russian propaganda for the last three years. Another group of researchers has a list of over 200 websites that they say regularly pushed out Russian propaganda material during last year's election, reaching 15 million Americans through social media and other online dissemination.
The propaganda strategy capitalized on, according the Washington Post, "the online world’s fascination with 'buzzy' content that is surprising and emotionally potent, and tracks with popular conspiracy theories about how secret forces dictate world events." It also noted that one particularly subversive strategy was to use websites that look like legitimate news sources and plant the misleading or erroneous stories in the middle of those sites, thereby lending the inaccurate piece credibility.
At least one of the researchers equated the propaganda as equivalent to a massive media ad buy for the Trump campaign on the order of what a Super PAC might do for a candidate.
Despite the overt support for Donald Trump, one expert sees the propaganda effort as not necessarily in the tank for one candidate over the other. From WaPo:
A former U.S. ambassador to Russia, Michael A. McFaul, said he was struck by the overt support that RT and Sputnik expressed for Trump during the campaign, even using the #CrookedHillary hashtag pushed by the candidate.
McFaul said Russian propaganda typically is aimed at weakening opponents and critics. Trump’s victory, though reportedly celebrated by Putin and his allies in Moscow, may have been an unexpected benefit of an operation that already had fueled division in the United States. “They don’t try to win the argument,” said McFaul, now director of the Freeman Spogli Institute for International Studies at Stanford University. “It’s to make everything seem relative. It’s kind of an appeal to cynicism.”