Can you set the Default Web Site's status to Stopped in IIS on the WFE servers, and still have access to your SharePoint 2013 site? We are attempting to do this for security reasons.
SharePoint stops the Default Website when you set up a web application on port 80 with no host header. It is highly recommended that stop the Default IIS web site because if some start this one, SharePoint can see many health related problem. In Many cases customer deleted the Default IIS web sites to avoid any unexpected error.
I am little surprise why it is running on your IIS, if you already install the SharePoint.
Another issue due to Default IIS site: http://absolute-sharepoint.com/2013/02/troubleshooting-setting-up-an-environment-for-apps-for-sharepoint-2013.html