mirrored site

Hi. During my usual checkups on a client website I've come across a very strange issue on the site and I hope that you will be able to help me. I suspect that my clients website has either been hacked or "mirrored". The issue is that all of a sudden the search console is reporting thousands of...

If I create a mirrored site of my competitors will that hurt their natural ranking? One of my sites was mirrored and I lost all ranking for the keywords I was targeting. Since then I have deleted the site and plan on installing a robots.txt file or some javascript that will prevent future...