they told me in whmcs.com that status folder only contains index.php but wiki says the folder also needs status.php

If the WHMcs wiki says that it should contain a status.php file then contact WHMcs Support and tell them that it says that, You may then get a better anwser and help out others.

zoom, please direct your WHMCS related questions to the company. The built the software.

something like this http://phpsysinfo.sourceforge.net ?