As you know, Office 365 provide quite a lot of security feature, one of them – called Safe Links – rewrite URL’s written in Office documents, emails or Teams message.

Well, you can add your organization logo on notification and warning pages when suspicious links have been detected and clicked on.

To do so, you need to have configure your Azure AD branding options and enable the option from the Security administration portal (https://security.microsoft.com/) under the Email & collaboration\Policies & rules\Threat Policies\Safe Links configuration blade

Edit the Safe Links policy you want to add your organization branding; the company branding option is available under the Protection Settings