Strange Computer Happenings

Something strange has happened today.  First, while on Yahoo I tried to click on a couple of articles and the website said connection refused.  Second, while on YouTube I tried to sign-in to leave a comment to a video and Chrome said that multiple files where being downloaded to my computer then it asked me if I wanted to allow this or deny it.  The file it was trying to download was named ajax.  I clicked deny and then cleared the download.