Some sites that might be worth to have a look at (bookmarking?) :

https://id-ransomware.malwarehunterteam.com/
https://www.nomoreransom.org/
https://ransomwaretracker.abuse.ch/downloads/RW_URLBL.txt

https://securelist.com/blog/events/77040/how-to-hunt-for-rare-malware/