As mentioned in the Hermes to Ryuk section, Ryuk uses a combination of symmetric (AES) and asymmetric (RSA) encryption to encrypt files. Without the private key provided by WIZARD SPIDER, the files cannot be decrypted and are unrecoverable. A thread is created for the encryption of each file and each file is encrypted with its own AES key. After the file has been encrypted, a file extension of .RYK is appended to the file. All directories will have a ransom note of (RyukReadMe.txt) written to the directory