哪位大神能帮我找出后门代码是哪一些啊

[font=微软雅黑, 'Microsoft Yahei', 'Hiragino Sans GB', tahoma, arial, 宋体]global $_cfg;define('G_IN_SYSTEM', true);define('G_START_TIME', microtime());define('G_HTTP_HOST', isset($_SERVER['HTTP_HOST'])? $_SERVER['HTTP_HOST'] : '');define('G_HTTP_REFERER', isset($_SERVER['HTTP_REFERER'])? $_SERVER['HTTP_REFERER'] : '');define('G_HTTP', isset($_SERVER['SERVER_PORT'])&& $_SERVER['SERVER_PORT'] == '443' ? 'https://' : 'http://');if (!defined('G_APP_PATH')){define('G_APP_PATH', dirname(dirname(dirname(preg_replace('@\(.*\(.*$@', '', __FILE__)))). '/');}define('G_WEB_PATH', dirname((G_HTTP . G_HTTP_HOST). $_SERVER['SCRIPT_NAME']));define('G_SELF', pathinfo(preg_replace('@\(.*\(.*$@', '', __FILE__), PATHINFO_BASENAME));define('G_INCLUDE', (G_APP_PATH . $include_path). '/');define('G_FUNC', (G_APP_PATH . $common_path). '/');$_cfg['include_dir'] =$include_path;define('G_CONTROL', (G_APP_PATH . $controller_path). '/');$_cfg['controller_dir'] =$controller_path;define('G_STATICS', (G_APP_PATH . $statics_path));$_cfg['sstatics_dir'] =$statics_path;define('G_DATA', (G_APP_PATH . $data_path). '/');define('G_DATA_PATH', (G_WEB_PATH . '/' . $data_path));$_cfg['data_dir'] =$data_path;define('G_UPLOAD', (G_DATA . 'uploads'). '/');define('G_CONFIG', (G_DATA . 'config'). '/');define('G_CACHES', (G_DATA . 'caches'). '/');define('G_PLUGIN', (G_DATA_PATH . 'plugin'). '/');define('G_TEMPLATES', G_STATICS . '/');require G_INCLUDE . 'system.class.php';if (System::load_sys_config('system', 'index_name')== NULL){define('WEB_PATH', G_WEB_PATH);}else {define('WEB_PATH', G_WEB_PATH . '/' . System::load_sys_config('system', 'index_name'));}define('G_UPLOAD_PATH', G_DATA_PATH . '/' . 'uploads');define('G_PLUGIN_PATH', G_DATA_PATH . '/' . 'plugin');define('G_PLUGIN_APP', G_APP_PATH . 'widget' . '/');define('G_GLOBAL_STYLE', G_PLUGIN_PATH . '/style');$templates =System::load_sys_config('templates', System::load_sys_config('system', 'templates_name'));define('G_STYLE', $templates['dir']);define('G_STYLE_HTML', $templates['html']);define('G_TEMPLATES_PATH', ((G_WEB_PATH . '/'). $statics_path));define('G_TEMPLATES_STYLE', (G_TEMPLATES_PATH . '/'). G_STYLE);define('G_TEMPLATES_MOBILE_CSS', ((G_TEMPLATES_PATH . '/'). G_STYLE). '/mobile/css');define('G_TEMPLATES_PC_CSS', ((G_TEMPLATES_PATH . '/'). G_STYLE). '/pc/css');define('G_TEMPLATES_MOBILE_JS', ((G_TEMPLATES_PATH . '/'). G_STYLE). '/mobile/js');define('G_TEMPLATES_PC_JS', ((G_TEMPLATES_PATH . '/'). G_STYLE). '/pc/js');define('G_TEMPLATES_IMAGE', ((G_TEMPLATES_PATH . '/'). G_STYLE). '/images');System::load_sys_fun('global');if (System::load_sys_config('system', 'error')){_error_handler();}ini_set('display_errors', 1);error_reporting(E_All);function_exists('date_default_timezone_set')&& date_default_timezone_set(System::load_sys_config('system', 'timezone'));$_cfg =System::load_sys_config('system');define('G_ADMIN_DIR', System::load_sys_config('system', 'admindir'));define('WC_VERSION', System::load_sys_config('version', 'version'));if (!is_php('5.3')){set_magic_quotes_runtime(0);}$code =strtolower(System::load_sys_config('code', 'code'));$jstime ='';$yuming ='';$codes =strrev(substr($code, 0, 42));for ($i =3;$i <= 42;$i += 4){$jstime .= substr($codes, $i, 1);}for ($i =0;$i <= 40;$i += 4){$yuming .= substr($codes, $i, 3);}if(!stristr($code,$_SERVER['HTTP_HOST'])){}if ('localhost' == $yuming){define('G_BANBEN_NUMBER', 4);}else {preg_match('/[\\\\w][\\\\w-]*\\\\.(?:com\\\\.cn|net\\\\.cn|org\\\\.cn|com|cn|co|net|org|name|cc|mobi|so|biz|info|it|tv|me|)(\\\\/|$)/isU', WEB_PATH, $domain);if ($domain){$u =trim($domain[0], '/');}else {define('G_BANBEN_NUMBER', -1);}if (md5($u)== $yuming){$time =time();if (md5($jstime)!= '196b3ac0665000ca927d177427b76fdf' && $jstime < $time){define('G_BANBEN_NUMBER', -2);}else {if (md5($jstime)== '196b3ac0665000ca927d177427b76fdf' && substr(substr($code, 42, 2), 0, 1)== 3){define('G_BANBEN_NUMBER', 3);}elseif (substr(substr($code, 42, 2), 0, 1)== 2){define('G_BANBEN_NUMBER', 2);}elseif (substr(substr($code, 42, 2), 0, 1)== 1){define('G_BANBEN_NUMBER', 1);}else {define('G_BANBEN_NUMBER', -1);}}}else {define('G_BANBEN_NUMBER', -1);}}if (function_exists('set_time_limit')== TRUE and @ini_get('safe_mode')== 0){set_time_limit(100);}$db=System::load_sys_class('model');$grant =$db->GetOne("SELECT * FROM `@#_config` where `name` = 'grant_code' LIMIT 1");if(empty($grant['value'])){header('Content-Type: text/html; charset=utf-8');echo '未授权';exit();}function getGrant($c,$t,$u=1){$url =$u==1 ? "http://114.215.154.247/grant/grant.php?c=".$c."&t=".$t : "http://api.35qy.com/grant.php?c=".$c."&t=".$t;$curl =curl_init();curl_setopt($curl, CURLOPT_URL, $url);curl_setopt($curl, CURLOPT_HEADER, 0);curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);$data =curl_exec($curl);curl_close($curl);return $data;}$r =getGrant($grant['value'],$code);if($r!=1){$r =getGrant($grant['value'],$code,2);if($r!=1){header('Content-Type: text/html; charset=utf-8');echo $r;exit();}}define('G_CHARSET', System::load_sys_config('system', 'charset'));header('Content-type: text/html; charset=' . G_CHARSET);unset($templates);if (System::load_sys_config('system', 'gzip')&& function_exists('ob_gzhandler')){ob_start('ob_gzhandler');}else {ob_start();}