(Using Windows 8, have Google Chrome, currently using Avast) For a couple days now my facebook notifications have been popping up on my desktop. It visibly looks like it could be Google Chrome, which I have, as the 'x' symbol to exit out of the notifications resembles the symbols on google chrome tabs. I had looked it up and thought it was something to do with Chrome and so I went to my setting and clicked 'do not show notifications from any site' in the privacy section under notification. For the rest of the day I hadn't noticed it popping up, but then my computer needed to update, so I updated it, and then it started happening again despite it showing that the notifications are off. So it led me to believe that it's some sort of virus.
The links the notifications send me seem to be the actual facebook site, but the mobile version. The link itself looks normal as well. I've had no suspicious advertisements so I don't think it's adware. My computer has been going particularly slow and a lot of small stuff has been happening lately and I'm concerned that I have spyware.
I will try to update this post with screenshots of them.