Click on this link to visit the GitHub site where Leo Stone has posted some code which might just figure out the key required to unencrypt a Hard Drive encrypted by Petya Ransomeware. He suggests to try finding the key using an image copy of the Petya encrypted Hard Disk,. That way the original may not be harmed.  

Disclaimer: if you use Leo Stone’s code and method, you do so at your own risk. Loe also suggested to make and use an image copy of the encrypted hard Drive so as not to potentially damage the original. Leo’s code may find the key, or it may not. Playing around with the encrypted Hard Drive may damage it to the point that even if you pay the Ransom, you may not be able to reteive your data from said hard drive. I again state that following Loe Stone’s method as posted on GitHub is done at your own risk. Do your own Due Diligence. You could lose all the data on the hard drive.

Posted by Vincent Banial