I got a message this morning that I was accepted into a sub that I never heard about, as if I had applied (but I didn't). It seemed to be a notification, not a

I got a message this morning that I was accepted into a sub that I never heard about, as if I had applied (but I didn't). It seemed to be a notification, not a message. I don't see it now. I'm guessing it's related to the hack, but it's not obvious what the scam or purpose was.