In the meantime... I was looking around and I saw under an ad the link "ad options"... I clicked there and... there is a link for deactivating the plugin (I can give you the page address but I don't write it here for now). Ok... now it seems to have deactivated the ads on the pages, but I still have several hyperlinks on the texts of the pages and some tabs that open automatically, so it is become less annoying but is still installed.