Recently a new client of mine was infected by a ransomware virus( since this infection, his previous IT consultant has gone underground). All of his Microsoft Office files are encrypted and his backup drive is badly corrupted. However, I was able to restore one file from the drive and so I possess the same file in it's encrypted and non-encrypted form. Is there a way for me to find the encryption key from these two files? I tried one utility from Panda Security, but it did not help. Does anyone have any suggestions?