Unknown files in WordPress core

Hello,

I have installed Wordfence on my website yesterday, and got 3 error messages this morning:

Unknown file in WordPress core: wp-includes/load.php.orig
Type: File
Filename: wp-includes/load.php.orig
File Type: Core
Details: 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.

Unknown file in WordPress core: wp-includes/functions.php.orig
Type: File
Filename: wp-includes/functions.php.orig
File Type: Core
Details: 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.

Unknown file in WordPress core: wp-admin/includes/upgrade.php.orig
Type: File
Filename: wp-admin/includes/upgrade.php.orig
File Type: Core
Details: 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.

My website does not appear to be different today, and it is not indexed yet (work in progress). WordPress was updated at least once in the last week, since I started with a fresh installation. Could that be causing the problem?

What should I do with these three files – is it something to be worried about?

Thank you in advance!