It sounds like your email accounts have indeed been compromised, and it's crucial to take immediate action to secure them. Here are steps you can follow to regain control and secure your accounts:
- Revoke User Access: Immediately revoke access to your accounts to prevent further unauthorized access. You can do this by using PowerShell commands to revoke sign-in sessions for your Microsoft 365 accounts. For example:
ReplaceRevoke-MgUserSignInSession -UserId <your-email-address><your-email-address>with your actual email address. - Change Your Passwords: Change the passwords for both of your email accounts. Make sure to create strong, unique passwords that are not easily guessable.
- Enable Multi-Factor Authentication (MFA): If you regain access, enable MFA for added security. This will help protect your accounts even if someone has your password.
- Review Account Activity: Check your account activity for any unauthorized logins or changes. Look for suspicious activity such as changes to your recovery email or security questions.
- Secure Your Devices: Since you mentioned reinstalling Windows, ensure that your devices are free from malware. Use reputable antivirus software to scan and clean your devices.
- Check for Mail Forwarding or Rules: Review your email settings for any suspicious forwarding rules or filters that may have been set up by the attacker. Remove any that you did not create.
- Contact Support: If you cannot regain access to your accounts or if the recovery email is still under the hacker's control, contact Microsoft Support for further assistance.
- Monitor for Further Issues: Keep an eye on your accounts and any linked services (like Epic Games and Steam) for unusual activity. Change passwords for those accounts as well if you suspect they may also be compromised.
Taking these steps can help you regain control of your accounts and protect your personal information.