Bing malware detection... On pages with /?xxx which are not on server

Well thing is simple, one of my websites got few months ago malware (I just noticed that), I noticed that malware is found on all pages like domain.com/?something

Question, why it is working ?? I do not have anything like that in htaccess (just redirect www to non www, index.html to domain), website is simple HTML without some fancy scripts...

Any ideas ???