Files with dxxd suffix can be typically encountered as files encrypted and renamed by the DXXD ransomware.
DXXD file extension - DXXD ransomware affected file
What is dxxd file? How to open dxxd files?
File type specification:
File extension dxxd seems to be mainly related to a ransomware labeled the same way - DXXD. Not different from other ransomware, it also encrypts and renames users files and demands ransom.