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, PayPal and Google+ were all affected, with Russia adapting techniques from digital marketing to reach audiences across multiple channels.
The committee has yet to say whether it endorses the findings, although it plans to publicly release the report alongside another one.