Emsisoft Decrypter for Philadelphia will decrypt the Philadelphia strain of ransomware which was designed by the author of Stampado.
This particular ransomware was written in AutoIT and uses AES-256 to encrypt targeted files and will assign a .locked file extension to them. Decryption can be a bit tricky due to the file name encryption. This fact will require you to compare the file size of the original file and round it up to the next 16 byte. For example, if the original file was 1020 bytes, the encrypted file will show 1024.
Emsisoft Decrypter for Philadelphia works by dragging and dropping both the encrypted file and the non-encrypted original into the decrypter.