Cybereason security researcher Amit Serper has found a way to prevent the Petya (NotPetya) ransomware from infecting computers.
“Researchers find creating a read-only “perfc” file on Windows stops the current “Petya” ransomware variant from executing locally.” Read the article for the details.
How to Enable the NotPetya/Petna/Petya Vaccine
To vaccinate your computer so that you are unable to get infected with the current strain of NotPetya/Petya/Petna (yeah, this naming is annoying), simply create a file called perfc in the C:\Windows folder and make it read only. For those who want a quick and easy way to perform this task, Lawrence Abrams has created a batch file that performs this step for you.
Please note that he batch file will also create two addition vaccination files called perfc.dat and perfc.dll. While my tests did not indicate that these additional files are needed, I added them for thoroughness based on the replies to this tweet.
This batch file can be found at: https://download.bleepingcomputer.com/bats/nopetyavac.bat
For those who wish to vaccinate their computer manually, you can do so using the following steps. Please note that these steps are being created to make it as easy as possible for those with little computer experience. For those who have greater experience, you can do it in quite a few, and probably better, ways.
