microsoft defender offline scan

Yes. That can happen because Microsoft Defender Offline restarts the PC and runs the scan outside the normal Windows environment. If BitLocker is enabled on the system drive, the restart into the offline environment can trigger BitLocker recovery, so Windows asks for the 48-digit recovery key.

Microsoft documents this behavior and recommends suspending BitLocker protection before running Microsoft Defender Offline. Otherwise, the device might prompt for the BitLocker recovery key when it restarts into the offline scan environment.

Key points:

1. This is expected behavior when BitLocker is enabled.
2. The key being requested is the BitLocker recovery key.
3. If the correct key is entered, the device can continue into the offline scan.
4. To avoid the prompt next time, suspend BitLocker protection before starting the offline scan.

BitLocker can also ask for the recovery key when it detects a possible unauthorized access attempt or certain hardware, firmware, or software changes. A reboot into the Defender Offline environment fits that kind of scenario.

References:

• Run and review the results of a Microsoft Defender Offline scan
• BitLocker overview