This is a recurring pro-Kremlin disinformation narrative regarding the downing of flight MH17, aimed at obscuring Russia's responsibility for the tragedy.
A Joint Investigation Team (JIT) was established to conduct the criminal investigation of the downing of the Malaysian Airlines flight MH17. The JIT comprises officials from the Dutch Public Prosecution Service and the Dutch police, along with police and criminal justice authorities from Australia, Belgium, Malaysia and Ukraine.
The JIT has concluded that flight MH17 was shot down on 17 July 2014 by a missile of the 9M38 series, launched by a BUK-TELAR, from farmland in the vicinity of Pervomaiskiy. At that time, the area was controlled by pro-Russian fighters. The BUK-TELAR was brought in from the territory of the Russian Federation and subsequently, after having shot down flight MH17, was taken back to the Russian Federation. On 24 May 2018, JIT stated that the BUK-TELAR that was used to down MH17 originates from the 53rd Anti Aircraft Missile brigade, a unit of the Russian army from Kursk in the Russian Federation. The JIT reached this conclusion after extensive comparative research. An animation of this comparative research is available here.
The Joint Investigation Team issued international arrest warrants in June 2019 for four individuals identified as being complicit in the shooting down of MH17: three Russian military and intelligence officers Igor Girkin, Sergey Dubinskiy, Oleg Pulatov and Ukrainian national Leonid Kharchenko, commander of the military combat unit in Donetsk. Their trial will begin On 9 March 2020. They will be prosecuted for their involvement in the murder of the 298 passengers aboard MH17, which was brought down by a Russian Buk missile.
For more cases on MH17, see here.