What would you do if a stranger hugged you?

I don't give a flying fuck about there looks, gender, or build, they would still be a stranger regardless and these aspects wouldn't change my reaction. I would be weirded out, possibly frightened as well. I don't have much muscle mass as of now, so if this person is of a an average build and is dangerous, I would have a lot of difficulty with asserting force and getting that person off of me.