It is absolutely coming from the fastonlineusers code. I positively narrowed this problem down to their code on my website as well.
I was getting the same thing as you, along with several different toolbars trying to install on me while on my own website! Apparently I was receiving too many hits per hour(?).
After removing their code from my website, and following spyware removal instructions on MajorGeeks.com’s forum, I have taken care of these problems on my website and on my computer due to fastonlineusers malicious code.
Here’s the link to the thread noted above. Hope this helps!
https://forums.majorgeeks.com/showthread.php?t=35407
