I did a quick search, didn't see any threads but I'm sure this is not something new. If anyone has any ideas, please let me know.
In Google SERPs, a clien'ts site is appearing with a strange string of text added to the end of the page's URL. It looks like this:
example.com/index.html?sms_ss=twitter&at_xt=4ddaadf6dad1f079,0
This is a static html site, only a few pages. I've done a quick scan of the code and the only funny thing I've found is this:
at the very beginning of the sitemap.txt file.