: Visit facebook.com/hacked immediately. This is the most reliable way to secure your account.
You received a notification about a login from an unrecognized location or device. fb-hack
People are receiving friend requests from a "new" account using your name and photo (this is often a rather than a direct hack). How Hackers Get In What to do if your account has been hacked - Facebook : Visit facebook
: If possible, attempt recovery from a phone or computer you have previously used to log into Facebook. Facebook's security algorithms are more likely to trust the request from a recognized device. People are receiving friend requests from a "new"
: Look for a message from Facebook regarding an email or password change. These emails often contain a special link that allows you to reverse the change and secure your account if it wasn't you. Signs You’ve Been Hacked Your password or email address has been changed.
If your Facebook account has been compromised, or you're seeing signs like posts you didn't write or login alerts that aren't you,