I can't guess what malware did this to my brother and client PCs but I'm running into systems that we can't repair the boot. Even with other tools like EasyBCD and such. This is not limited to Windows 10 but 7, 8, 8.1, XP and you get the idea.

What this means is nothing has fundamentally changed. We must maintain backups and test the recovery options.

My last encounter (I see this stuff weekly) was a Dell with a blinking cursor. The Dell diags (press D on power up) seems to tell me it was not hardware. So I used the Windows 10 Recovery with full restore files and the machine came back fine. Yes, the user files are gone but that was on backups so they lost nothing.