Some Soviet aircraft are shamless copies of US aircraft, like the B-29, the F-111, and the Spcace Shutle.
Maybe the next obvious knock-off will be the Mig-69 Fluffer. Huh-huh-huh.
The Tu-4 Bull was a shameless copy reverse engineered from three interred B-29s. Apparantly Stalin wanted exect copies (altho the engines were different), and they even included service dings/scratches and patches over flak damage that were present on the originals.
The Su-24 and Buran shuttle may look similar to, but are indeed very different aircraft from, the F-111 and Space Shuttle. Think of them more as applying similar enough engineering knowledge to common challenges, resulting in aircraft that bear a passing cosmetic resemblence to each other. But not anywhere close to shameless copies.
Same is true of both the Tu-160 Blackjack (looks sorts like a B-1), An-124 Condor (C-5) and even the MiG-25/31 family (they look like fat, twin-tailed A-5 Vigilantes)