your password has expired

I went to open Zoom as usual. It asked me to sign in which it sometimes does. I signed in as usual and got a message to say my password had expired. I have never had this message before and have not set an expiry date on my password.

I went to the Zoom website where it said my password had been compromised on a third party app and I needed to reset my password. 

I did join another persons Zoom call last night and something popped up which took to be part of the entry process and clicked on.

Is this a scam? Has my security been compromised? I don't see any other posts about this. 

Would be very grateful for any insight.

many thanks