There are websites, presumably selling free ebooks (in Bulgarian): https://icsicommunity.org/, https://adorota.wpdevcloud.com/, https://izteglite-pdf-kniga.com/ that all link to http://yourbooklibrary.net/ or https://searchvipbooks.com/ (probably there are others, I’ve only found those). They are scams (if you add the URL parameter “p” you can change the name of the book). If you log in or try to read/download the book, the website sends you to a login page, which if you change the URL you can see the “other” services they offer (movies and music). They also have a number on their site: 1-925-206-3859 and a location. The company that is behind the site is called Draxton Media LTD
I found an article, saying they are already scammers (fraudulently charges credit cards after they have subscriptions), but I would like a better in-depth look at what’s happening and to alert anyone else stumbling upon the site.