Let me provide some information about the notification to rebuild your data, @Howdy74.

When the warning message happens when you log in to your QuickBooks file, then this isn't a scam. Unless, there is someone who call you or email you about this. 

The warning is a reminder for you to rebuild your company file to fix some possible data issues. For more information, you may check out this article:  Verify and Rebuild Data in QuickBooks Desktop.

Additionally, I've attached an article you can utilize to learn how to get different QuickBooks Desktop tools to help fix problems and errors: Fix common problems and errors with the QuickBooks Desktop Tool Hub.

Let us know if there's anything that I can help with rebuilding your data in QuickBooks. The Community is always here to assist. Stay safe!