I have been hit too.. My movie server.. 2800 movies and 72G of music on an Ubuntu server. I am deducing that it was via Samba.. port 445..
Here is my case:
https://id-ransomware.malwarehunterteam.com/identify.php?case=08dd4c6463880fc2dd9acacf7e48f77a65242aa3
CH01_20180702215041.mp4.nampohyu
!DECRYPT_INSTRUCTION.TXT