Stuff like that happened repeatedly: GAZ Chaika was a copy of Packard; SM-1 computer was a copy of PDP 11/34; Tu-144 looked just like Concorde, etc. etc.
Tu-144 was not a copy of the Concorde. (Convergent evolution is not the same as copying a design!)
The Soviets did clone a lot of DEC gear but I don't think SM-1, specifically, was a DEC clone. (In this lastmost case, the Soviets were left cloning computer equipment because it was forbidden to export to COMECON states)
Another example I forgot: the first Soviet nuke was directly copied from the stolen Fat Man design. Of course later they did novel stuff, especially the fusion designs of Sacharov et al.
It is well known that KGB got hold of the Concorde blueprints, so yeah, not a direct copy but certainly a lot of influence in that design. Again. the details like engine performance made the difference: apparently Tu144 had to continuously use afterburners to stay supersonic. It was also quite unreliable---I've heard that towards its end of life it was just flying cargo and airmail.
The Concorde was much smaller, and lacked one of the major innovations of the Tu-144 -- forward flap canards to improve handling on a larger jet.
Probably for the better. The Tupolev killed a lot of its passengers, and it was almost immediately withdrawn from service after the first few incidents. The Concorde, a simpler and smaller design, served for decades.