Last week we started our technical analysis on Petya (also called NotPetya) and its so-called “killswitch.” In that blog post we mentioned that Petya looks for a file in the Windows folder that has the same filename (no extension) as itself (for example: C:\Windows\Petya). If it exists, it terminates by calling ExitProcess. If it doesn’t exist, it creates a file with the attribute DELETE_ON_CLOSE. This seems to imply that instead of a killswitch, this file is meant to be a marker to check and see if the system has already been infected.
After…
Article Link: https://blog.fortinet.com/2017/07/08/petya-s-master-boot-record-infection