Comment by Dylan16807

Just booting opens up the encrypted drive. Windows gets the key out of the TPM.

Which leaves an enormous attack surface. If you can break Windows before logging in, you can effectively bypass bitlocker.

"Windows loads some file in System Volume Information automatically" is not evidence of a backdoor. And you have to put specific exploit files in there to turn this into an attack. You don't just make the folder.

It's still possible this is a backdoor, I guess, but there's nothing as blatant as you're implying.