Yup, that would indicate that likely a bot is trying to guess it’s way in.
You are still safe.
The only weird thing here is that Microsoft lets such things bother you instead of guessing that you didn’t teleport to Brazil and instead putting a little extra burden on the Brazil end before sending you an email.
If you’re still feeling worried, the biggest thing you can do is enable two-factor auth (which you should do anyway), or even better: enable something like passkeys which are very secure and also easier than username/password.
Two-factor/password manager is the “remember to brush and floss” of the security industry, so… Please do those things. :)