The Internet Research Agency (IRA), a state-sponsored "troll factory" in St. Petersburg.

But much of the information Mueller published on Friday about the agency's efforts to influence the election had already been published last October — in an article by a Russian business magazine, RBC.

In a 4,500-word report titled "How the 'troll factory' worked the U.S. elections," journalists Polina Rusyaeva and Andrey Zakharov offered the fullest picture yet of how the "American department" of the IRA used Facebook, Twitter and other tactics to inflame tensions ahead of the 2016 vote. The article also looked at the staffing structure of the organization and revealed details about its budget and salaries.