It is generally not recommended to use USB drives from unknown sources due to the potential risks of security threats. If you are considering using an unknown source, below is a list of suggested steps to take.:

1. Research the device origins and user reputation, if possible.
2. Scan the drive for malware with an antivirus.
3. Create a new, unique password to access the drive.
4. Keep the drive in a secure location to limit its access.
5. Immediately delete the files if the drive is unneeded.