some one hacked my account

If your account has been hacked, here are the steps you should take to regain control:

1. Reset Your Password: Immediately change your password to something strong and unique. If you can still access your account, do this right away.
2. Secure Your Account: If your account is synced from Active Directory, reset the password in Active Directory as well. If your identity is federated with Microsoft 365, change the password in your on-premises environment.
3. Update App Passwords: If you use app passwords, make sure to delete the old ones and create new ones, as they are not automatically revoked when you reset your password.
4. Enable Multifactor Authentication (MFA): This adds an extra layer of security to your account. It's highly recommended for accounts with admin privileges.
5. Revoke User Access: Use PowerShell to revoke any active sessions using the stolen credentials. This prevents the attacker from accessing your account further.
6. Investigate Suspicious Activity: Check for any unusual activity in your account, such as sent emails that you did not authorize, changes to your profile, or suspicious inbox rules.
7. Contact Support: If you are unable to regain access or if you need further assistance, contact Microsoft support for help.
8. Monitor Your Accounts: Keep an eye on your account for any further suspicious activity and consider reporting it to your IT department if applicable.

By following these steps, you should be able to regain control of your account and secure it against future attacks.

References:

• Respond to a compromised cloud email account
• Secure and Restore Email Function to a Compromised Microsoft 365 Mail Enabled Account
• Common symptoms of a compromised Microsoft 365 email account
• What to do if you've been a victim of a phishing scam