Petya ransomware uses an exploit called "EternalBlue" through the "Server Message Block version 1" (SMBv1) — a file sharing protocol which was developed more than 30 years ago. The same exploit was also used by another ransomware "WannaCry".
The National Security Agency "NSA" has been reported to have known this exploit and used it for their own offensive works without informing the public.
This ransomware encrypts infected harddrive and asks for a ransom of $300 USD worth of bitcoins.
