OpenToYou targets Windows OS and its method of distribution is currently unknown. Once a system is infected, OpenToYou creates a password string, uses SHA-1 to produce an encryption key from the password, and then uses that encryption key to encrypt the system’s files using the RC4 algorithm. It appends .-email@example.com to encrypted files and drops a ransom note named !!!.txt.
- Emsisoft provides more information about OpenToYou, including a free decryption tool, here.