One user at my site has reported that he reaches the content at /var/www when browsing to any of the vhosts at my server. As far as I’m aware, my Apache server does not contain a document root that references this folder. On top of that, this user seems to be the only one experiencing the issue. According to his ISP, the issue isn’t caused by them, yet, on his mobile connection, he can access the site. When browsing to my server’s IP, he also receives the correct content from the default vhost.

What could be the possible causes of this issue and how can I get it to stop? I’ve explored pretty much every option I could think of.