Hi,
Thank you for your answer.
I have been assisted early by an professional who remotely connected and installed all these tools (combofix, malwarebytes and TDSkiller) and probably removed the virus. I plan to reinstall completely my system to make sure everything is cleaned, but actually I am very afraid about my files. When I open any files I am redirected to the website http://mblpcblock.in/ , where the virus ask me to pay to have a decryptor. I don’t know what to do :(.