Issue

[Habs]

I signed into a random email I made for a silver xbox account and there is some random alt email on it. I have never seen the email in my life and I certainly didn't add it, but the password hasn't changed?

Is this a possible Rat/Keylog?
I checked my main shit nothing changed on them, PayPal, email, FK, etc...

 

[Damian]

Most likely. It sounds strange.
You'd be better off contacting Microsoft support and getting it removed.
If you're worried then perform virus scans.