Russia allegedly used every major social media platform to influence the 2016 US election, a report claims.
The Washington Post has obtained a draft of the report, which it says includes claims that YouTube, Tumblr and Instagram – as well as Facebook and Twitter – were allegedly targeted.
This week, the US Senate will publish the report, which exposes the scale of Russian disinformation efforts.
Its authors criticise the “belated and uncoordinated 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, Pinterest and Google+ were all affected, as well as email services including Google’s Gmail, Microsoft’s Hotmail and Yahoo.
The committee has yet to say whether it endorses the findings, although it plans to publicly release the report alongside another one.
The BBC has asked Russia’s Embassy in the UK for comment.
The research details a vast campaign spearheaded by the Internet Research Agency – 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.
“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 Internet Research Agency’s base of operations.
The agency 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.