Managing personal Outlook.com account settings, security, and privacy
Hello, thank you for reaching out to Microsoft Q&A.
Have you tried resetting your Microsoft account password using the link here?
https://account.live.com/ResetPassword.aspx
Before you look to reset your password, double-check that you are using the correct email address when logging in. Open the link in an incognito tab and paste the link above.
If you successfully reset your password, go to the Security Settings page for your Microsoft account and enable two-factor authentication for added security.
https://account.live.com/proofs/Manage
In addition, scroll down until you find Sign out everywhere, and select it.
Microsoft will then sign your account out from all trusted devices, typically within 24 hours.
If you received the threatening message in your email, delete the email and check your email rules. Delete all emails from the sender and the rules.