Decrypt Any Ransomware Encrypted Data Files in Help, my files are encrypted! Posted February 3 · Report reply Hello @shyam punjabi, Welcome to the Emsisoft Support Forums. NOSU is a newer variant of the STOP/DJVU family of ransomware and is not supported by our decryption tool. Despite that, I would like for you to run the STOP/DJVU decryption tool anyway. That will accomplish a couple of things. First, it will deactivate and remove any malware that was installed by the ransomware. This will prevent new files from being encrypted and will prevent re-encryption if files are restored from a backup. Second, the decryption tool will determine the ID of the encrypted files. Any ID ending in t1 is an Offline ID anything else is an Online ID. This is important as it tells us how the encryption key was generated. There may be multiple Ids, especially if communication between the target system and the command & control server is interrupted for any reason, or because the file encryption was done in stages to avoid detection. An Offline ID means that the encryption key pair was generated locally and the encryption key is encoded in a file. An Online ID means the encryption key pair was generated and stored on a remote command & control server under the control of the ransomware gang responsible for encrypting your files. Why is this important? The ID of the file(s) is how private encryption keys are identified. If we have a private encryption key matching the ID for a file(s) then that can be used to decrypt the file(s). However, this is all contingent on us having a matching private encryption key in our database. The downside of all this is that we are not currently in possession of private encryption keys for the NOSU variant of STOP/DJVU. To Download the STOP/DJVU decryption tool visit https://www.emsisoft.com/ransomware-decryption-tools/stop-djvu Also, see https://support.emsisoft.com/topic/32045-about-the-stopdjvu-decrypter/ for more information on the STOP/DJVU decryption tool.