This scam has whiskers on it, but because it returns every 6 months or so to claim new victims, I want to describe it so you can be on the lookout:
A Facebook Friend contacts you through Facebook Messenger, saying: “Is it you in this video?!” Below the message is a link to YouTube or another official-looking video site.
If you click the video, you are presented with a Facebook sign-in screen, asking for your email and password…
DON’T sign in on that screen and DON’T click the video link!
The link does not go to YouTube or any other legitimate website, and the Facebook sign-in prompt is a phishing site that is NOT part of Facebook. Anyone who types a password into that box is delivering their Facebook credentials directly to the bad guys. And the friend who sent you that fake video message? Their account was likely stolen from them in the same manner.
If you get this kind of Facebook Messenger message, contact that friend immediately outside of Facebook. Call, email, text, just reach out to them and let them know that their Facebook account may be compromised, and that they should change their password.
If someone is calling you complaining about your message, then perhaps you were hoodwinked! Change your Facebook password ASAP, and consider turning on their 2FA feature, to safeguard against this in the future.