Hi, I'm John! I will help you with this.
Microsoft Q&A is public, and we can only provide information. It is beyond our capability to assist directly with the account or login-related issues.
Are you seeing these unsuccessful sign-in attempts mainly on your @outlook, @gmail and @yahoo aliases connected to your Microsoft account?
You can check here https://account.live.com/Activity
If you notice an alias getting targeted, you can disable sign-in for that specific email. This helps block hackers who might have gotten that address from a data leak.
Once you know which alias is being targeted the most:
- Please note that if it's your primary alias, you won’t be able to disable it. You can only disable sign-in for @gmail and @yahoo aliases, or @outlook/@hotmail if they are not set as the primary alias.
- Go to https://account.live.com/SignInPreferences
- Find the email address being targeted in the list and uncheck the option to use it for signing in
- Click "Save"
Next, just to be safe, I’d recommend to sign out everywhere. Visit: https://account.live.com/proofs/manage/additional Scroll down to Sign me out and select "Sign me out".
"How to help keep your Microsoft account secure" https://support.microsoft.com/account-billing/how-to-help-keep-your-microsoft-account-secure-628538c2-7006-33bb-5ef4-c917657362b9
I really hope this information is helpful! Let me know if you have any further questions or concerns.
Regards,
John J.D.