emails replaced with "Best Private Tools & Hotmail Mix/Data Access"

This situation indicates a likely account compromise and/or mailbox data tampering. Use the following steps to secure the account and attempt recovery:

1. Secure the device
   • Run a full antivirus/malware scan on the PC or device used to access Outlook.com before changing any passwords. If using Windows 10/11 or 8.1, ensure Windows Defender is enabled and updated, then perform a full scan.
2. Secure the Microsoft account
   • Change the Microsoft account password immediately using the official flow: sign in and change the password, ensuring it is a strong password.
   • If sign-in is not possible, use the password reset flow to regain access.
3. Run the hacked/compromised account recovery process
   • Follow the official Microsoft guide for hacked or compromised accounts. This is the only supported method to recover a compromised Microsoft account and related Outlook.com mailbox.
   • If the attacker has changed security information and the account recovery web form fails, there is no alternate supported method for Microsoft Support to restore access.
4. Check and clean account settings
   • After regaining access, review Outlook.com account settings for malicious changes:
     • Connected accounts
     • Forwarding
     • Automatic replies
   • Remove any unknown forwarding addresses, connected accounts, or auto-replies that could be used to exfiltrate or manipulate mail.
5. Investigate and restore email where possible
   • If this is a Microsoft 365 mail-enabled account (rather than consumer Outlook.com), an admin can:
     • Revoke active sign-in sessions using Revoke-MgUserSignInSession.
     • Review and remove suspicious MFA devices and app consents.
     • Check for and remove malicious mailbox forwarding using Get-Mailbox and Get-InboxRule as described in the compromised email account response guidance.
   • For on-premises or backup-based environments (Exchange Server), if messages were deleted or overwritten by a retention policy or other process, restore from backup or recovery database as documented, then merge the restored data with current data.
6. If Outlook desktop data exists locally
   • If Outlook was used with a POP/IMAP profile and a local PST file exists, restore from that PST backup by opening it in Outlook (File → Open & Export → Open Outlook Data File) and copying items back into the mailbox.
7. If self-service recovery fails
   • For Outlook.com consumer accounts, use the in-product Help to contact support (requires sign-in) or the dedicated “can’t sign in” support entry point.
   • If the account recovery form continues to fail and security info has been replaced, Microsoft Support cannot override the automated process or restore the account.

References:

• How to recover a hacked or compromised Microsoft account
• Respond to a compromised cloud email account
• Items that you want to retain are removed by MRM 2.0 in Exchange Server
• How do I recover my old email messages, my contacts and everything else I had in Outlook? - Microsoft Q&A
• my microsoft account has been compromised - Microsoft Q&A
• My account got hacked - Microsoft Q&A
• Verify my backup email address for my Outlook.com account