Create a Custom Application with a signature and attach it to a security policy, or create a custom application and define an application override policy--A custom application allows you to customize the definition of the internal application--its characteristics, category and sub-category, risk, port, timeout--and exercise granular policy control in order to minimize the range of unidentified traffic on your network. Creating a custom application also allows you to correctly identify the application in the ACC and traffic logs and is useful in auditing/reporting on the applications on your network. For a custom application you can specify a signature and a pattern that uniquely identifies the application and attach it to a security policy that allows or denies the application.
Alternatively, if you would like the firewall to process the custom application using fast path (Layer-4 inspection instead of using App-ID for Layer-7 inspection), you can reference the custom application in an application override policy rule. An application override with a custom application will prevent the session from being processed by the App-ID engine, which is a Layer-7 inspection. Instead it forces the firewall to handle the session as a regular stateful inspection firewall at Layer-4, and thereby saves application processing time.
https://docs.paloaltonetworks.com/pan-os/10-0/pan-os-admin/app-id/manage-custom-or- unknown-applications.html#id74b58a78-164f-4dc5-aa4e-31ce62f2af0d

https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-admin/threat-prevention/prevent-credential- phishing/set-up-credential-phishing-prevention