When using encrypting file system (EFS), what happens to an unencrypted file copied into an encrypted folder?

When an unencrypted file is copied into an encrypted folder that utilizes the Encrypting File System (EFS), the file automatically gets encrypted. This behavior is a key feature of EFS, which is designed to protect files and folders on the file system by applying encryption transparently.

The encryption occurs because the file inherits the encryption attribute from the folder into which it is copied. EFS manages this process seamlessly, ensuring that any files placed within an encrypted directory are protected without requiring additional steps from the user. Therefore, once the unencrypted file is copied to the encrypted folder, it becomes encrypted and secured the next time it is accessed.

This automatic encryption helps maintain the confidentiality and security of sensitive data without needing users to specifically encrypt each file individually. It's an effective way of ensuring that all files within a certain directory are uniformly protected under the same encryption scheme.