Russia used every major social media platform to try to influence the 2016 US election, a report claims.
New research says YouTube, Tumblr, Instagram and PayPal - as well as Facebook and Twitter - were leveraged to spread propaganda.
The report, released today by the US Senate, exposes the scale of Russian disinformation efforts.
Its authors criticise the "belated and unco-ordinated response" by tech firms.
The report was put together by University of Oxford's Computational Propaganda Project and the social network analysis firm Graphika.
It is the first analysis of millions of social media posts provided by Twitter, Google and Facebook to the Senate Intelligence Committee.
While Facebook and Twitter have previously disclosed Russian interference, little has been known about the use of other platforms.
The report suggests YouTube, Tumblr, PayPal and Google+ were all affected, with Russia adapting techniques from digital marketing to target audiences across multiple channels.
"It's a whole family of social media sites," says Philip N Howard, director of the Oxford Internet Institute. "We think the goal was to make the campaigns seem more legitimate."
The research details a vast campaign spearheaded by the Internet Research Agency (IRA) - a Russian company that has been described by the United States Intelligence Community as a troll farm with ties to the Russian government.
The report says Russia had a particular focus on targeting conservatives with posts on immigration, race and gun rights.
There were also efforts to undermine the voting power of left-leaning African-American citizens, by spreading misinformation about the electoral process.
Another report, also released today by the Senate, by the research firm New Knowledge, similarly highlights Russia's efforts to target African-Americans.
It explains how Russia's IRA were focused on "developing Black audiences and recruiting Black Americans as assets," which included encouraging activists to stage rallies.
One IRA campaign highlighted in the Oxford and Graphika paper, Black Matters US, existed across Twitter, Facebook, Instagram, YouTube, Google+, Tumblr and PayPal. These various accounts would promote each other's posts and events.
When Facebook suspended the group on its platform, the group's Twitter account complained about the move and accused the social network of "supporting white supremacy".
"What is clear is that all of the messaging clearly sought to benefit the Republican Party - and specifically Donald Trump," the report says.
"Trump is mentioned most in campaigns targeting conservatives and right-wing voters, where the messaging encouraged these groups to support his campaign. The main groups that could challenge Trump were then provided messaging that sought to confuse, distract and ultimately discourage members from voting."
While the data used by the researchers was provided by Facebook, Twitter and Google, their findings criticise the "belated and uncoordinated response" from these companies to Russia's disinformation campaign.
The researchers highlight details that could have led internet companies to detect interference earlier, such as the use of the Russian rouble to buy advertisements and internet signatures relating to the IRA's base of operations.
The BBC has asked Russia's Embassy in the UK for comment.
The IRA was among the three companies indicted earlier this year, as part of special counsel Robert Mueller's investigation into Russian interference in the 2016 election. Twelve of the agency's employees faced indictment charges, as well as its alleged financier, Yevgeny Prigozhin.
"Social media have gone from being the natural infrastructure for sharing collective grievances and co-ordinating civic engagement, to being a computational tool for social control, manipulated by canny political consultants and available to politicians in democracies and dictatorships alike," the report says.