Atlantic Security Conference

Have you ever wondered how a boot process works? How a computer detects which operating system it needs to load? Or what is the impact if that single sector in your harddisk is compromised?

In this presentation, we are going to look into how Petya, a ransomware, can overwrite an MBR (Master Boot Record), both in MBR- and GPT-style disk, with its malicious code. Then, we are going to follow the code in the MBR and show how a simple malicious kernel code can take control of the boot process until you pay the ransom. I will show a demo on how to debug the MBR to see how the actual native code executes without any API.  

We are also going to see how we can use a combination of different tools to figure out how a ransomware can infect the very first sector of a harddisk. Tools, such as, Disk Management, DISKPART, WinObj, Process Monitor, and HDHacker. And of course, x64dbg and ollydbg for debugging the ransomware in application-level. And finally, we are going to see how to use Bochs debugger to analyze the malware while it runs its own kernel code.