The default grey box with the WordPress logo screams "templated." If you run a brand, membership site, or client site, you need to upgrade the aesthetic. WordPress Security - Pantheon Docs
or /login : Common aliases that often redirect to the main login page. Special Installations wp login
Related search suggestions (may help further): I'll provide terms. The default grey box with the WordPress logo
For most websites, you can find the login page by adding one of the following paths to the end of your domain name: or client site