This plugin GETs the server header and saves the result to the knowledge base. Nothing strange, just do a GET request to the url and save the server headers to the kb. A smarter way to check the server type is with the hmap plugin.
This plugin doesn’t have any user configured options.
For more information about this plugin and the associated tests, there’s always the source code to understand exactly what’s under the hood:
Plugin source code
Unittest source code
This plugin has no dependencies.