Encrypted by Osiris ransomware

Can anybody help me with Osiris ransomware that encrypted all my files and now it claims 2.5 Bitcoin for decryption. I have tried different antiviruses like Kaspersky, AVG and Dr.Web, Malwarebytes Antimalware and this manual guide – http://www.trymytools.com/remove-osiris-ransomware-and-restore-the-encrypted-files/
But unfortunately nothing helped.