SHADOW SSDT HOOK

HOOK 和 UNHOOK SHADOW SSDT 跟之前的 HOOK/UNHOOK SSDT 类似，区别是查找SSSDT的特征码，以及根据索引计算函数地址的公式，还有一个就是吧跳转函数写在什么位置，SSDT的时候是写在蓝屏函数里了。

一、获得 w KeServiceDescriptorTableShadow的地址

这个跟获得 KeServiceDescriptorTable 差不多，唯一不同就是特征码：

ULONGLONG GetKeServiceDescriptorTableShadow64()
{
PUCHAR StartSearchAddress = (PUCHAR)__readmsr(0xC0000082);
    PUCHAR EndSearchAddress = StartSearchAddress + 0x500;
PUCHAR i = NULL;
UCHAR b1=0,b2=0,b3=0;
ULONG templong=0;
ULONGLONG addr=0;
for(i=StartSearchAddress;i<EndSearchAddress;i++)
{
if( MmIsAddressValid(i) && MmIsAddressValid(i+1) && MmIsAddressValid(i+2) )
{
b1=*i;
b2=*(i+1);
b3=*(i+2);
if( b1==0x4c && b2==0x8d && b3==0x1d ) //4c8d1d
{
memcpy(&templong,i+3,4);
addr = (ULONGLONG)templong + (ULONGLONG)i + 7;
return addr;
}
}
}
return 0;
}

二、根据 X INDEX  获得 T SSSDT  函数在内核里的地址

原理跟获得 SSDT 函数在在内核里的地址差不多，先获得 W32pServiceTable的地址，然后再获得每个函数的偏移地址，在把偏移地址与 W32pServiceTable相加。为什么下面的计算公式是 W32pServiceTable + 4 * (index-0x1000)呢？其实这只是个理解上的问题。SSDT 函数的起始 INDEX 是 0x0，SSSDT 函数的起始 INDEX 是 0x1000，但函数地址在 W32pServiceTable 是从基址开始记录

的（假设 W32pServiceTable 的地址是 0xfffff800~80000000，第 0 个函数的地址就记录在 0xfffff800~80000000，第 1 个函数的地址就记录在0xfffff800~80000004，第 2 个函数的地址就记录在 0xfffff800~80000008，以此类推）。

ULONGLONG GetSSSDTFuncCurAddr64(ULONG64 Index)
{
ULONGLONG    W32pServiceTable=0, qwTemp=0;
LONG     dwTemp=0;
PSYSTEM_SERVICE_TABLE    pWin32k;
pWin32k = (PSYSTEM_SERVICE_TABLE)((ULONG64)KeServiceDescriptorTableShadow + sizeof(SYSTEM_SERVICE_TABLE));
W32pServiceTable=(ULONGLONG)(pWin32k->ServiceTableBase);
ul64W32pServiceTable = W32pServiceTable;
qwTemp = W32pServiceTable + 4 * (Index-0x1000);    //这里是获得偏移地址的位置，要HOOK的话修改这里即可
dwTemp = *(PLONG)qwTemp;
dwTemp = dwTemp >> 4;
qwTemp = W32pServiceTable + (LONG64)dwTemp;
return qwTemp;
}

三、修改SSSDT里的地址

还是跟 SSDT 类似，修改 W32pServiceTable+4*index 地址的 DWORD 值（偏移地址值）。

VOID ModifySSSDT(ULONG64 Index, ULONG64 Address)
{
    ULONGLONG               W32pServiceTable=0, qwTemp=0;
    LONG                    dwTemp=0;
    PSYSTEM_SERVICE_TABLE   pWin32k;
    KIRQL                   irql;
    pWin32k = (PSYSTEM_SERVICE_TABLE)((ULONG64)KeServiceDescriptorTableShadow + sizeof(SYSTEM_SERVICE_TABLE));  //4*8
    W32pServiceTable=(ULONGLONG)(pWin32k->ServiceTableBase);
    qwTemp = W32pServiceTable + 4 * (Index-0x1000);
    dwTemp = (LONG)(Address - W32pServiceTable);
    dwTemp = dwTemp << 4;
    irql=WPOFFx64();
    *(PLONG)qwTemp = dwTemp;
    WPONx64(irql);
}

第一个代理函数用机器码写成，总共就 14 个字节，前 6 字节为 ff 25 00 00 00 00，后 8 字节为第二个代理函数的地址（JMP QWORD PTR）。

VOID ModifySSSDT(ULONG64 Index, ULONG64 Address)
{
ULONGLONG    W32pServiceTable=0, qwTemp=0;
LONG     dwTemp=0;
PSYSTEM_SERVICE_TABLE    pWin32k;
KIRQL    irql;
pWin32k = (PSYSTEM_SERVICE_TABLE)((ULONG64)KeServiceDescriptorTableShadow + sizeof(SYSTEM_SERVICE_TABLE));    //4*8
W32pServiceTable=(ULONGLONG)(pWin32k->ServiceTableBase);
qwTemp = W32pServiceTable + 4 * (Index-0x1000);
dwTemp = (LONG)(Address - W32pServiceTable);
dwTemp = dwTemp << 4;
irql=WPOFFx64();
*(PLONG)qwTemp = dwTemp;
WPONx64(irql);
}

代理函数地址：

ULONG64 ProxyNtUserPostMessage(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
{
if( NtUserQueryWindow(hWnd,0)==MyProcessId && PsGetCurrentProcessId()!=(HANDLE)MyProcessId )
{
DbgPrint("Do not fuck with me!");
return 0;
}
else
{
DbgPrint("OriNtUserPostMessage called!");
return NtUserPostMessage(hWnd,Msg,wParam,lParam);
}
}

注意UnHOOK就是把真正的函数地址给填写回去

VOID UNHOOK_SSSDT()
{
ModifySSSDT(IndexOfNtUserPostMessage, (ULONG64)NtUserPostMessage);
DbgPrint("UNHOOK_SSSDT OK!");
}

执行效果测试

以下是窗口攻击函数：

int main2()
{
DWORD pid, wpid, i, j;
HWND hWnd;
gogogo:
printf("pid: ");
scanf("%ld", &pid);
for (i = 100; i<0xffffff; i += 2)
{
GetWindowThreadProcessId((HWND)i, &wpid);
if (wpid == pid && IsWindowVisible((HWND)i) == 1)
{
hWnd = (HWND)i;
for (j = 0; j<0x10000; j++)
{
PostMessage(hWnd, j, 0, 0);
}
}
}
printf("Ok!");
getchar();
getchar();
goto gogogo;
return 0;
}

通过HOOK PostMessage 来保护自己不被干掉：

至于Un SSSDT HOOK 是和SSDT思路一样的，也是自己加载相关内核模块，得到一些地址，然后在通过驱动通讯，在内核里获得一些地址，最后计算出来函数的真正地址，然后把原地址填写回去（这个地方就是继续hook一遍）就行了。直接把资料相关代码粘贴过来吧：

R3的代码：

#include <stdio.h>
#include <direct.h>
#include <Windows.h>
#include "EnumDrv.h"
#include "DrvCtrl.h"

HANDLE hMyDrv;

void PrintAddressByIndex()
{
LONG64 id=0;
ULONG64 addr=0;
st:
printf("Input index (HEX without \"0x\" like: 1000, input -1 to exit): ");
scanf("%llx",&id);
if (id<0) return;
IoControl(hMyDrv ,CTL_CODE_GEN(0x807), &id, 8, &addr, 8);
printf("%llx\n",addr);
getchar();
goto st;
}

DWORD FileLen(char *filename)
{
WIN32_FIND_DATAA fileInfo={0};
DWORD fileSize=0;
HANDLE hFind;
hFind = FindFirstFileA(filename ,&fileInfo);
if(hFind != INVALID_HANDLE_VALUE)
{
fileSize = fileInfo.nFileSizeLow;
FindClose(hFind);
}
return fileSize;
}

CHAR *LoadDllContext(char *filename)
{
DWORD dwReadWrite, LenOfFile=FileLen(filename);
HANDLE hFile = CreateFileA(filename, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_EXISTING, 0, 0);
if (hFile != INVALID_HANDLE_VALUE)
{
PCHAR buffer=(PCHAR)malloc(LenOfFile);
SetFilePointer(hFile, 0, 0, FILE_BEGIN);
ReadFile(hFile, buffer, LenOfFile, &dwReadWrite, 0);
CloseHandle(hFile);
return buffer;
}
return NULL;
}

ULONG64 GetWin32kImageBase()
{
PIMAGE_NT_HEADERS64 pinths64;
PIMAGE_DOS_HEADER pdih;
char *NtosFileData=NULL;
NtosFileData=LoadDllContext("c:\\win32k.dll");
pdih=(PIMAGE_DOS_HEADER)NtosFileData;
pinths64=(PIMAGE_NT_HEADERS64)(NtosFileData+pdih->e_lfanew);
return pinths64->OptionalHeader.ImageBase;
}

void GetOriAddress()
{
ULONG64 W32pServiceTable, Win32kBase, Win32kImageBase, Win32kInProcess=0, retv;
IoControl(hMyDrv ,CTL_CODE_GEN(0x806), NULL, 0, &W32pServiceTable, 8);
Win32kBase = GetWin32kBase();
CopyFileA("c:\\windows\\system32\\win32k.sys","c:\\win32k.dll",0);
Win32kImageBase = GetWin32kImageBase();
printf("W32pServiceTable:      %llx\n", W32pServiceTable);
printf("WIN32K.SYS base:       %llx\n", Win32kBase);
printf("WIN32K.SYS image base: %llx\n\n\n", Win32kImageBase);
ULONG index=0;
if ( Win32kInProcess==0 )
Win32kInProcess = (ULONGLONG)LoadLibraryExA("c:\\win32k.dll",0, DONT_RESOLVE_DLL_REFERENCES);
for(index=0;index<825;index++)    //825是WIN7X64上SSSDT的函数个数
{
ULONGLONG RVA=W32pServiceTable-Win32kBase;
ULONGLONG temp=*(PULONGLONG)(Win32kInProcess+RVA+8*(ULONGLONG)index);
ULONGLONG RVA_index=temp-Win32kImageBase;
retv = RVA_index+Win32kBase;
printf("Shadow SSDT Function[%ld]: %llx\n",index,retv);
if(index % 100 ==0)
{
printf("Press any key to continue......\n");
getchar();
}
}
}

int main()
{
hMyDrv=openDriver();
GetOriAddress();
uninstallDriver();
return 0;
}

宋孖健，13