A leak of internal data from the Kremlin-backed Internet Research Agency discovered by The Daily Beast serves as the first confirmation that the Russian troll farm deployed its online agitators on Reddit as part of its campaign to interfere in American politics.

The leak also reveals 21 Tumblr accounts, including login credentials, run by the Internet Research Agency (IRA). The listing for the leak offers “American proxies” for Reddit and viral meme site 9Gag. The leak comes after months of speculation from Reddit users that the site had been targeted by a foreign influence campaign.

Content from IRA-backed websites like BlackMattersUs.com received hundreds—and sometimes thousands—upvotes on subreddits like r/The_Donald and r/HillaryForPrison in the run-up to the 2016 election. Trolls purporting to represent the troll farm promised an Ask Me Anything session in October, but the Q-and-A never occurred.

When The Daily Beast reached out to Reddit for comment, a public relations representative requested screenshots and details of the leak, which The Daily Beast provided. The spokesperson told The Daily Beast the company would be in touch if it had any further comment.

Reddit then ignored repeated further requests for comment.

9Gag is a viral meme site that is one of the 300 most visited sites in the world, according to the web traffic analysis site Alexa. 9Gag also did not respond to a request for comment at press time.

The leaks indicate, at least 21 Tumblr accounts were creations of the Internet Research Agency. The names of the accounts showed bizarre attempts at concocting slang terms, apparently in an effort to appear authentically African-American, like “Ghetta Blasta,” “Hustle In A Trap,” and “Swag In The Rain.” Those users uniformly pushed mostly relatable memes about being black in America, then filtered in invitations to protests by IRA groups like Blacktivist, along with conspiracy theories about Hillary Clinton.

All of the accounts have since been shuttered. Tumblr would not explain to The Daily Beast the circumstances behind the end of those accounts, but provided a generic statement that referred to its proactive cooperation with law enforcement. Screenshots from the leak indicate more than 21 Tumblr accounts were IRA fabrications. Tumblr would not say how many such accounts it has uncovered in total.

Tumblr had previously ignored requests for comment from BuzzFeed and CNN, which had repeatedly asked for its policies on the Kremlin-backed propaganda sites that went unchecked in its communities for years.

The Daily Beast posed several questions to Tumblr and its parent company Oath about the 21 accounts named in the leak’s listing on the Russian “information exchange” Joker.Buzz, which frequently auctions off stolen or confidential documents, including asking how many total IRA accounts have been pulled by the platform.

An Oath spokesperson responded with the following statement.

“We’re committed to creating platforms consumers can trust, and any abuse of our services is deeply concerning to us. Like others in the technology industry, we’re continuously investigating and referring criminal and state-sponsored activity on our platforms to appropriate law enforcement authorities.”

When pressed to elaborate about Russian troll farm activity, the company did not respond.