Conspiracy theory with no evidence given; a straw man argument, attacking an imaginary position of the opponent. No serious sources suggest China "created" the SARS-CoV-2 virus, which has caused the COVID-19 outbreak.
A recent analysis of the genome sequence of SARS-CoV-2 virus found no evidence that it was developed artificially in a lab or otherwise engineered. The virus comes from a family of viruses originating in animals that includes others such as SARS and MERS. It was first reported in the Chinese city of Wuhan in central China in late 2019 and has been rapidly spreading across the world.
The claim that "Russia is blamed for fake gas attacks" ostensibly refers to the war in Syria and is another example of the straw man argument. Russia has never been accused of using chemical weapons during its military involvement in Syria; however, Russia has supported the Assad regime, which has used toxic gas against opposition strongholds.
The international investigation into the downing of flight MH17, which killed all 298 people onboard, has concluded that the perpetrators who fired the Russian-made BUK TELAR missile that shot down the plane were connected to Russian armed forces units. The ongoing trial in Amsterdam will evaluate the evidence produced by the investigation. Pro-Kremlin media have been aggressively attempting to question the legitimacy of the investigation and the Dutch judiciary. Examples of cases on MH17 can be found here.
This case is another example of how the pro-Kremlin disinformation machine exploits crisis situations like the current COVID-19 pandemic to spread disinformation about other topics and opportunistically adapts existing pro-Kremlin narratives to new contexts.