https://www.blackhat.com/docs/eu-15/materials/eu-15-Haken-Bypassing-Local-Windows-Authentication-To-Defeat-Full-Disk-Encryption-wp.pdf

An attack which is able to bypass Windows authentication, even in the presence of BitLocker full disk encryption, and thus allows an attacker to access a user’s data or install software. On systems effected this attack therefore bypasses all of the protections offered by BitLocker. ...READ MORE