HELLOKITTY contains an embedded RSA-2048 public key. This public key is SHA256 hashed and used as the victim ID within the ransom note. This RSA pubic key is also used to encrypt each file's symmetric key. For the symmetric key, HelloKitty generates a 32 byte seed value based on the CPU timestamp. A Salsa20 key is generated and encrypts a second 32 byte seed value. The encrypted result is XOR’d with the first seed, resulting in a 32 byte key used to AES encrypt each file. After each file is encrypted, the original file size, magic value of DE C0 AD BA, and AES key are encrypted with the public RSA key and appended to the file. HELLOKITTY and FIVEHANDS appends this additional metadata to the encrypted file, while DEATHRANSOM does not. Depending on the version, HELLOKITTY may or may not change the file extension. Other samples of HELLOKITTY have used an embedded NTRU public key instead of RSA