It seems pretty immature they cannot make unique address for each infection right? It would be much easier that way, then no communication would be necessary.
In my eyes this means that they don't really intend to recover the data if somebody is paying the ransom.
But I see a lot of desperate people thinking "let's pay and hopefully... ". Hopefully what? There are free programs that can protect the computers.
If I would make such ransomware I would not even bother to make an encryption that can be decrypted. One direction "encryption" is cheaper.