The Russian company that makes Buk air defense systems conceded that a Buk missile was responsible for the downing of Malaysian Airlines flight 17 on July 17, 2014.
Murder In The Sky: Malaysia Airlines Flight MH17
Business Insider: Russian has a brand new theory about what brought down a passenger plane in eastern Ukraine

Dutch and Malaysian investigators and local authorities work, on April 23, 2015 on the site where the bulk of the Malaysian Airlines flight MH17 was shot out of the sky near the village of Grabove in the self-proclaimed Donetsk People's Republic.