From 2-spyware.com
Josephnull ransomware is the threat that creates issues on the machine when files get locked and renamed.
Josephnull ransomware – cryptovirus that marks files using .crypted file appendix, but the name of the virus comes from a contact email – josephnull@secmail.pro and ransom note. The latter one is the pop-up program window that appears on the screen when your files get encrypted and machine affected. The message also appears as a text file named HOW_TO_DECYPHER_FILES.txt. Other files might get added, your desktop wallpaper can get changed to the particular picture with the ransom-demanding message.