Petya and Mischa ransomware, come as a package deal, distributed by its creators, Janus. They are very unusual in that they combine two different methods to encrypt user data. Unlike most other ransomware, Petya primarily encrypts MFT (Master File Table) and MBR (Master Boot Record). If Petya has insufficient privileges to access MBR on HDD (Hard Disk Drive), the Mischa module is deployed and encrypts files one by one.