BuzzFeed, Inc. is an American Internet media, news and entertainment company with a focus on digital media; it is based in New York City. BuzzFeed was founded in 2006 by Jonah Peretti and John S. Johnson III, to focus on tracking viral content. Kenneth Lerer, co-founder and chairman of The Huffington Post, started as a co-founder and investor in BuzzFeed and is now the executive chairman.
Buzzfeed was also a conduit in other Russiagate disinformation pieces. Buzzfeed Journalists Anthony Cormier and Jason Leopold reported that "President Trump Directed His Attorney Michael Cohen To Lie To Congress About The Moscow Tower Project" a story specifically denied by special counsel Robert Mueller.
"people involved with Russia, who have been murdered in Britain by the Russian state"
BuzzFeed “published the results of a long-running and in-depth investigation in 2017 in which it claimed that there are 14 cases of Russians, or people involved with Russia, who have been murdered in Britain by the Russian state, but which the British authorities have covered up (see https://www.buzzfeed.com/heidiblake/from-russia-with-blood-14-suspected-hits-on-british-soil?utm_term=.bkEjM8opP#.ropGB372Y ). The evidence is compelling.” 
Integrity Initiative connection
A BuzzFeed journalist, Craig Silverman, was mentioned peripherally in the Integrity Initiative leaks, where Chris Hernon followed his twitter account an operation that included engagement with "other users in our field".