Nasty defacement - so do not visit link to defaced website!
See: https://asafaweb.com/Scan?Url=chinese4fun.com
Custom errors are used to ensure that internal error messages are not exposed to end users. Instead, a custom error message should be returned which provides a friendlier user experience and keeps potentially sensitive internal implementation information away from public view.
Result
It looks like custom errors are not correctly configured as the requested URL contains the heading “Server Error in”.
Custom errors are easy to enable, just configure the web.config to ensure the mode is either “On” or “RemoteOnly” and ensure there is a valid “defaultRedirect” defined for a custom error page as follows:
polonus