I did receive a notification from Microsoft of a suspicous login about a week ago. The password for that account was a relatively strong one (upper/lower case,

I did receive a notification from Microsoft of a suspicous login about a week ago. The password for that account was a relatively strong one (upper/lower case, numbers and some symbols I think). It was an actual login, not just an attempt. I also don't use my Microsoft account for anything (no Windows/Xbox). So I'm inclined to say that they have had a breach.