新方法获取shadow ssdt地址---直接内存读取法（简单易懂），兼容XP、2003和WIN7

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xp sp3里面的：
nt!KeAddSystemServiceTable+0x1a:
80597810 8d88e03f5580    lea     ecx,nt!KeServiceDescriptorTableShadow (80553fe0)[eax]
80597816 833900          cmp     dword ptr [ecx],0
80597819 7546            jne     nt!KeAddSystemServiceTable+0x6b (80597861)

2003 企业版 sp2的：
nt!KeAddSystemServiceTable+0x1a:
80915116 8d8840f48980    lea     ecx,nt!KeServiceDescriptorTableShadow (8089f440)[eax]
8091511c 833900          cmp     dword ptr [ecx],0
8091511f 7546            jne     nt!KeAddSystemServiceTable+0x6b (80915167)

win7旗舰版sp1的：
nt!KeAddSystemServiceTable+0x1a:
83de0022 8d8840dbdb83 lea ecx,nt!KeServiceDescriptorTableShadow (83dbdb40)[eax]
83de0028 833900 cmp dword ptr [ecx],0
83de002b 7546 jne nt!KeAddSystemServiceTable+0x6b (83de0073)

上面都是 偏移0x1a，8d88占两个字节，所以在加上2，后面的四个字节就是shadow ssdt的地址了

所以就是 KeAddSystemServiceTable的地址+0x1a（偏移量）+2（汇编指令占用的两个字节）

//SSDT结构体
typedef struct ServiceDescriptorTable {
   unsigned int *ServiceTableBase;
   unsigned int *ServiceCounterTable;
   unsigned int NumberOfServices;
   unsigned int *ParamTableBase;
}ServiceDescriptorTable,*PServiceDescriptorTable;

PServiceDescriptorTable KeServiceDescriptorTableShadow;

NTSYSAPI
BOOLEAN
NTAPI
KeAddSystemServiceTable (
       IN PULONG_PTR Base,
       IN PULONG Count OPTIONAL,
       IN ULONG Limit,
       IN PUCHAR Number,
       IN ULONG Index
);

PULONG getAddressOfShadowTable()
{
    PULONG p;

    //兼容XP，2003和WIN7
    //nt!KeAddSystemServiceTable+0x1a:
    //83de0022 8d8840dbdb83    lea     ecx,nt!KeServiceDescriptorTableShadow (83dbdb40)[eax]
    //83de0028 833900          cmp     dword ptr [ecx],0
    //83de002b 7546            jne     nt!KeAddSystemServiceTable+0x6b (83de0073)

    //8d88两个字节，所以+2
    p = (PULONG)((ULONG)KeAddSystemServiceTable+0x1a+2);

    return (PULONG)(*p);
}

测试代码：
DbgPrint("address: 0x%X",getAddressOfShadowTable());
KeServiceDescriptorTableShadow = (PServiceDescriptorTable)getAddressOfShadowTable();
DbgPrint("num of services:%d",KeServiceDescriptorTableShadow[1].NumberOfServices);

下面是运行结果：
100.95681000  进入驱动程序入口！
100.96257782  address: 0x83D74B40
100.97072601  num of services:825