Did that Elbrus processor thingy ever take off? Don't think so, haven't heard of it for... A decade or so? (Except the name popped up somewhere the other day, probably in a rhetorical question like this, otherwise I wouldn't even have remembered it to mention here.)

So, assuming every PC in Russia isn't running on an Elbrus or something, they use the same Intel (and some AMD) and variosly-branded ARMs as everyone else. If anyone doesn't, it might be the Chinese, but I'm guessing the situation is pretty much the same there, too. More domestic ARM cloners than in Russia, probably.

So finding or inserting backdoors in "our" stuff is inserting backdoors in "their" stuff.