Managing personal Outlook.com account settings, security, and privacy
That sign-in prompt strongly indicates the account’s security info was changed and the account may be compromised.
Do these steps in order:
- Scan the PC for malware before changing anything
Open Windows Security, go to Virus and threat protection > Scan options > Full scan > Scan now. Microsoft recommends a full scan before changing the password. - Try the hacked-account recovery flow
Use the Microsoft hacked-account recovery process and start with the sign-in helper tool: Start - If the account still opens to an unknown verification email, use account recovery
On the sign-in page, select Forgot my password, then choose I think someone else is using my Microsoft account and follow the recovery steps. - If access is still possible anywhere, review recent activity immediately
Go to Security basics: https://account.microsoft.com/security
Select Review activity. If an entry is not recognized:- In Unusual activity, expand it and select This wasn't me.
- In Recent activity, expand it and select Secure your account.
- Change the password after the malware scan
From Security basics, select Change password and create a strong password. - Check account settings that are often changed after a compromise
Review:- connected accounts
- forwarding
- automatic replies
- Add another sign-in or verification method after recovery
Go to Advanced security options and select Add a new way to sign in or verify so recovery is easier if this happens again.
If sign-in is completely blocked, the sign-in helper is the main path to identify the available recovery options. Microsoft Support can be contacted through Contact Microsoft Support, but support agents are not allowed to send password reset links or access and change account details.