系统调用（四）：SSDT

查看SSDT和SSDTShadow

kd> dd KeServiceDescriptorTable
80553fa0  80502b8c 00000000 0000011c 80503000　　Ntoskrl.exe
80553fb0  00000000 00000000 00000000 00000000
80553fc0  00000000 00000000 00000000 00000000
80553fd0  00000000 00000000 00000000 00000000

kd> dd KeServiceDescriptorTableShadow
80553f60  80502b8c 00000000 0000011c 80503000　　Ntoskrl.exe
80553f70  bf999b80 00000000 0000029b bf99a890　　Win32k.sys
80553f80  00000000 00000000 00000000 00000000
80553f90  00000000 00000000 00000000 00000000

第一个DWORD指向函数地址表

kd> dds 80502b8c
ReadVirtual: 80502b8c not properly sign extended
80502b8c  8059a948 nt!NtAcceptConnectPort
80502b90  805e7db6 nt!NtAccessCheck
80502b94  805eb5fc nt!NtAccessCheckAndAuditAlarm
80502b98  805e7de8 nt!NtAccessCheckByType
80502b9c  805eb636 nt!NtAccessCheckByTypeAndAuditAlarm
80502ba0  805e7e1e nt!NtAccessCheckByTypeResultList

第三个DWORD为函数数量

第四个DWORD指向函数参数表

kd> db 80503000
ReadVirtual: 80503000 not properly sign extended
80503000  18 20 2c 2c 40 2c 40 44-0c 08 18 18 08 04 04 0c  . ,,@,@D........
80503010  10 18 08 08 0c 04 08 08-04 04 0c 08 0c 04 04 20  ............... 
80503020  08 10 0c 14 0c 2c 10 0c-0c 1c 20 10 38 10 14 20  .....,.... .8.. 
80503030  24 24 1c 14 10 20 10 34-14 08 0c 08 04 04 04 04  $$... .4........
80503040  0c 08 28 04 1c 18 08 18-0c 18 08 18 0c 08 0c 04  ..(.............
80503050  10 00 0c 10 28 08 08 10-1c 04 08 0c 04 10 08 00  ....(...........
80503060  08 04 08 0c 28 08 04 10-04 04 0c 0c 28 04 24 28  ....(.......(.$(
80503070  30 0c 0c 0c 18 0c 0c 0c-0c 30 10 0c 10 0c 0c 0c  0........0......

实验：在函数表尾部加一函数调用

测试代码

#include "stdafx.h"
#include <windows.h>

void __declspec(naked) MyIntWriteProcessMemory(HANDLE  hProcess,
  LPVOID  lpBaseAddress,
  LPCVOID lpBuffer,
  SIZE_T  nSize,
  SIZE_T  *lpNumberOfBytesWritten){
    __asm{
        mov eax,0x11c
        lea edx,[esp+4]
        int 0x2e
        ret
    }
}
int main(int argc, char* argv[])
{

    DWORD X=0xabcd;
    DWORD addr=0;
    DWORD dwProcessId = 0;
    DWORD check=0;
    printf("input Pid:");
    scanf("%x",&dwProcessId);
    printf("input addr:");
    scanf("%x",&addr);
    HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS,FALSE,dwProcessId);
    MyIntWriteProcessMemory(hProcess,(char*)addr,(char*)&X,(SIZE_T)4,(SIZE_T*)NULL);
    return 0;
}

#include "stdafx.h"
#include <windows.h>

int main(int argc, char* argv[])
{
    DWORD X=0x1234;
    DWORD PID=GetCurrentProcessId();
    printf("PID = %x\n",PID);
    printf("X = %x\n",X);
    printf("Xaddr = %x\n",&X);

    getchar();
    printf("X = %x\n",X);
    getchar();
    return 0;
}

kd> ed 80502ffc 805aa81c
WriteVirtual: 80502ffc not properly sign extended
kd> dds 80502b8c+115*4
ReadVirtual: 80502fe0 not properly sign extended
80502fe0  805aa81c nt!NtWriteVirtualMemory
80502fe4  8050322c nt!NtYieldExecution
80502fe8  8060f632 nt!NtCreateKeyedEvent
80502fec  8060f71c nt!NtOpenKeyedEvent
80502ff0  8060f7ce nt!NtReleaseKeyedEvent
80502ff4  8060fa5a nt!NtWaitForKeyedEvent
80502ff8  805c2798 nt!NtQueryPortInformationProcess
80502ffc  805aa81c nt!NtWriteVirtualMemory

kd> eb 8050311c 14

kd> ed 80553fa8 11d