Did you get an email from “Facebook” and click on the link? If so, you probably are the one that got hacked. It happened to my mom several months ago and I had to install an anti-virus program and it found some problems. I recommend AVG free as a starting point, works for most common viruses and other internet problems. Just do a Google search on “AVG Free” and do the download, then scan your computer.
Hover over the “Go Back” link and look in the bottom left corner of the screen. Does it say “http://facebook.com", if not you need to get your computer cleaned.
I did not click on any link. I Trash everything I get from FB.