Access Denied | Malicious?

Our website is not loading for me on Chrome + Torch and for some of our customers its giving the following error above. (see attachments).

We ran Wordfence and we got the following message (see image).

How can I solve this image given that it is effecting my wp-config.php file and it's a critical file?

I tried re-installing WP4.7 through WordPress under Dashboard>Updates but no luck.