There was a change in strategy this time around, the EU added. Instead of launching large efforts online, the Russians and the political figures linked to them preferred "smaller-scale," more regional influence campaigns that would be harder to catch.

The report writers credit Facebook, Google, Twitter and others with doing a better job of cracking down on misinformation that could have made Russia's meddling more effective. However, the EU also said that "more needs to be done" on the part of internet giant, including greater transparency for ad hosts and more cooperation with fact checkers. The Union planned to study the effectiveness of an existing Code of Practice and propose further efforts, possibly including regulations, if the current rules weren't deemed adequate.

Russia has historically denied interfering in foreign elections despite evidence to the contrary. It's not always effective, according to past reports, but the EU findings suggest that the country isn't about to give up any time soon.