Files with remk extension are files that were encrypted and had their suffix renamed by one of the variants of STOP ransomware.
REMK file extension - STOP Ransomware variant
What is remk file? How to open remk files?
File type specification:
File extension remk is used by one of the variants of STOP ransomware that appeared during the COVID-19 crisis (March 2020) and affected several hospitals. Pretty much like any other ransomware it encrypts users files, renames the file extension and demands ransom in bitcoins.
You can find decrypters for previous versions of STOP ransomware, so it's just matter of time before decrypter for this variant is available as well.