How did the Coot ransomware get on my computer? The instructions are placed on the victim’s desktop in the _readme.txt file. The STOP/DJVU ransomware encrypts the personal documents found on the victim’s computer, then displays a message which offers to decrypt the data if payment in Bitcoin is made. If you cannot open your images, documents, or files and they have a “.coot” extension, then your computer is infected with the STOP/DJVU ransomware.