Since the "Host" header has not yet been sent, Apache won't know which VirtualHost to send the request to, so it defaults to the very first VirtualHost on that IP, which in this case, is in /etc/httpd/conf/httpd-vhosts.conf, as it uses a ServerName of "localhost", since nothing specific seems approriate. (it could also be in the /etc/httpd/conf/ips.conf for a shared IP)