WaPo:

While much attention has focused on the question of whether the Trump campaign encouraged or conspired with Russia, the effort to target Sanders supporters has been a lesser-noted part of the story. Special counsel Robert S. Mueller III, in a case filed last year against 13 Russians accused of interfering in the U.S. presidential campaign, said workers at a St. Petersburg facility called the Internet Research Agency were instructed to write social media posts in opposition to Clinton but “to support Bernie Sanders and then-candidate Donald Trump.” 


That strategy could receive new attention with the release of Mueller’s report, expected within days.  

Sanders told Vermont Public Radio last year that one of his campaign workers figured out what was going on, alerted the Clinton campaign and told them, “I think these guys are Russians.” But Sanders said he never knew, and he later backed off his suggestion that his staff did. A spokesman referred questions to 2016 campaign manager Jeff Weaver, who said in an interview that Sanders “misspoke a little bit and conflated a few of the facts. . . . He did not know, I did not know, none of us knew” that Russia was behind the efforts. 

Only recently, with the latest analysis of Twitter data, has the extent of the Russian disinformation campaign been documented on that social media platform.