Oh btw, turns out it's not a ransomware. It may appear as that but the ransomware appearance is just a disguise, it's actually a wiper designed to render your PC inoperable permanently. When installed, Petya removes the master boot record (MBR) from your computer. The MBR is what contains your operating system (like Windows) and when you switch your computer on, it goes to the MBR to retrieve the necessary operating system files and load them into memory so you can reach the part of the operating system that you actually use. So Petya removes that and replaces it with the ransom note, therefore no access.
But it turns out it may have been a state-funded attack by Russia to attack Ukrainian organisations. So it's not financially motivated but political and was not intended to spread the way it did. However given that organisations are interconnected globally, overseas companies linked to these Ukrainian companies also got hit because Petya used international VPNs as a bridge to jump from one local area network (LAN) to another. Research shows that the recovery method of the malware is inoperable which means there was never an intent to fix the damage once a ransom was paid. So if your computer gets hit, that's it, game over.