Maybe it is just a stupid bot. I have daily 404s from different IP adresses trying to access urls like http://www.example.com/http://facebook.com/ or http://www.example.com/sms:+43123456789. The user agent of the bot I always see is something like Java/… This bot tries to follow all links, href, src, etc he can find.
Check if you maybe have the text (+0,48595,73506+-) somewhere on the referring page and what user agent is sent.
PS: If you want to search for something with a minus you can quote in on google like site:example.com “-text” will search for text on example.com which that contains “-text”. However, I think this will only find visible text on your page and not links, etc.