subdirectory that is not on my server

First, I apologize if this is not posted in the correct place but I really hope that there is someone out there that can help me.

The issue that that I am having is that we have our company website https://pelicanbroadband.com and somehow someone has attached https://pelicanbroadband.com/blanket/ to our site. I cannot find any compromise on my server, database, etc. I don’t know why or how this site is attached to our site.

The page I need help with: [log in to see the link]