Now I am successfully using WebClient.DownloadString to get file content from ESX server. My URI is something like:
https://<ip>/folder/<file-path>?dcPath=ha-datacenter&dsName=<datastore-name>
But how can I get a content of a hidden file (e.g. '.myfile')?
UPDATE: I have the 404 or Not Found error message when I receive a response from the server. And nothing happens when I open this url in my browser. May be there is exist a parameter like 'dcPath' (datacenter path) or 'dsName' (datastore name) for ESX https request to receive a content of a hidden file. Or may be there are ESX server's settings that enable receiving hidden files through the https?
Like @UnixShadow suggested you would need to set a mime-type for the file type/extension you are trying to access. But the real issue here is that static files that have the hidden attribute set will return a HTTP 404 or an Access Denied error when browsed.
Configuring access control for all Web files should always be implemented through NTFS permissions.