Facebook says it is aware of a glitch that is causing old posts and photos to suddenly appear at the top of a user's News Feed. The problem has been reported by many users since earlier this weekend and it appears to be a common glitch. Facebook is now working on a fix.
We are aware of this and are investigating, - Facebook
Users have seen some of their previously published content reposted as new without any of the accompanying likes or comments. You'll have to manually delete the reposts if they appear on your page.