Yes, this looks like it was the work of the Kremlin. Some might argue he would have been killed if it was, but I don't see how Putin isn't behind this.
The Kremlin should be given the chance to submit proof it wasn't the Russian government, but I don't think this will happen. The Western world must now gets its act together impose new and stricter sanctions on Putin and his regime. It's enough that he's gotton away with this kind of stuff, election interference and Ukraine invasion and paying no severe price.