It is a malicious software that blocks access to computers and data until a sum of money is paid. NotPetya is the second major global ransomware since WannaCry, which had infected about 3,00,000 computers across 200 countries in May. Similar to WannaCry, one of the means by which Petya spread was by exploiting the MS12-010 vulnerability, also known as EternalBlue. Microsoft had issued a security patch to fix it in March.
The Petya ransomware not only encrypts files, but also overwrites and encrypts the master boot record. It shuts down the system about an hour after the infection and asks for ransom on rebooting. Users will not be able to access the system till the infection is removed. The PC might be protected from the malware in case the user is able to disrupt the system reboot.
Ransomware is a piece of malicious software which takes control of your system and files. Upon taking over, it applies encryption on those files and asks for money for a key that can restore the files. The ransomware often scrambles file names and changes their extension.