Ban non-existing users

Is there an option to auto ban hosts that were trying to login using a non-existing username?

I see the plugin can auto-ban anyone who used username “admin” to login. However, some of my sites get hundreds of daily logins from different IPs) that try to use non-existing usernames.

I saw some other plugins offer this option, but I don’t want to install another security plugin (which will duplicate most of iThemes Security’s features).