The Soviet Union, officially the Union of Soviet Socialist Republics, The USSR, whatever you want to call it, still exists today. Even though it dissolved on 26 December 1991., you can still work with something that The USSR used as an official thing.
I'm talking about it's country code top-level domain, .su.
.su it's still alive since 1990., and you can register it on websites like www.register.su
It's kind of fascinating that a dead country still lives, on a beautiful thing called internet.