Hello,
This is indeed a hot topic and not only related to our Dynamics 365 Business Central, other SaaS hosters face similar incidents. See for instance:
gomox.medium.com/google-safe-browsing-can-kill-your-startup-7d73c474b98d
All we can do is to ask you to follow the process here:
support.google.com/.../99020
If you own a site marked as dangerous or deceptive:
Follow the instructions to fix the problem and request a review via developers.google.com/.../request_review
The issue is not related to Dynamics 365 Business Central but more or less to the domain setup. The first article, not generated by Microsoft or Microsoft support, provides a few suggestion you can do to deal with this issue. There may be other reports from other entrepreneurs that found other ways to prevent this from happening.
Most likely, changing logo’s or changing alternate ways to logon to Dynamics 365 Business Central via Azure AD authentication in stead of NavUserPassword may not prevent the issue either. Apart from that, the few reports that we received related to similar issues, all were about partners / customers using NavUserPassword.
It may still be worthwhile exploring Azure AD Authentication, but there are no guarantees that this will resolve it for you.
Hope it helps you somehow to get rid of this unwanted warning from Google as it is not a nice experience you do not want to see when it is a false positive.
Thanks.