I believe this to be the original sample. There have been multiple strains emerging lately as the malware is adapted by others. Cylance has stated that they've seen at least 27 unique hashes for WannaCry malware.
https://github.com/ytisf/theZoo/tree/c4f...e.WannaCry
https://github.com/ytisf/theZoo/tree/c4f...e.WannaCry