I know this has been suggested before. Dunno if it's even true. But I could see why Russia might use Jew baiting as a weapon. Rather than promote anti-Americanism directly, which would risk turning Americans off due to patriotism, this form of information war would encourage Americans to blame the other, the Jew, for anything they dislike and undermine confidence in US governmental institutions. There is certainly great harmony between anti-Semitic white nationalists and pro-Russian politics. The alt-right is probably the most pro-Russian political faction in the US.

I still think most Judeo-obsessives are sincere idiots. But it is plausible that Russia would latch onto it as a form of disinfo and to promote conspiracy theories that further Russian interests.