Hi, I have received a notice from our WordPress Scan that says:
Unknown file in WordPress core: wp-includes/js/thickbox/css.php
File type: Core
Issue first detected: 9 hours 39 mins ago.
This file is in a WordPress core location but is not distributed with this version of WordPress. This is usually due to it being left over from a previous WordPress update, but it may also have been added by another plugin or a malicious file added by an attacker.
Can you advise me on what I should do?