Some Ukrainian company was somehow responsible for distributing this nasty strain of ransomware. This is what they posted on their website in response (a machine translation into English, at least):
Considering how destructive this is, the “apology” is a bit half-hearted!
log into console
run create database dbname;
GRANT ALL PRIVILEGES ON *.* TO ‘username’@’localhost’ IDENTIFIED BY ‘password’; < this gives the user privileges to everything.
GRANT ALL PRIVILEGES ON mydb.* TO 'myuser'@'%' WITH GRANT OPTION;
this gives privileges to just mydb. you can probably combine these two statements to create a user and give it permission to only one DB