Can you tell me if this is valid?
 

Someone that I am hosting is currently running VB, I don't think I have access to post in the sections because I'm not a owner, but anyways I got a email from my server about these files

/home/b/public_html/includes/class_functions.php:1552: }
/home/b/public_html/includes/class_functions.php:1553: mail($suppmail,"c99shell v.".$shver." feedback #".$ticket,$body,"FROM: ".$suppmail);
/home/b/public_html/includes/class_functions.php:1554: echo "Thanks for your feedback! Your ticket ID: ".$ticket.".";

I noticed the c99shell, is that a legit and valid file or did someone exploit his forums?

I can't even download it to see what the file looks like, so if you can reply or email me [email protected] and let me know, thank you!