过TP之创建CreateMyDbgkDebugObjectType

丁侦球

因为TP有个线程不断的对这个清零,测试过以下方案:
1.直接恢复结构,马上会被清零,od提示无法附加进程,放弃
2.inlinehook,调用ob***之前恢复结构,因为tp清零太快,od提示无法附加进程,放弃

还有个难点就是debugport清零了,我已经解决了,至于方法就不直接说了,提示一下:
修改31处系统函数的debugport偏移,但是有一处tp有检测,我是用Inlinehook绕过的,不修改这一处偏移,在自己的代码里写上新偏移.
至于是检测了哪一处,你们自己测试,我曾经inlinehook了31处才确定的.汗啊!
等哪天tp增加检测的位置,我那31个inlinehook代码又要用上了.

总结:
1.不能修改TesSafe.sys代码,有校验,修改任何一个字节会重启,如果有能力过掉校验就没问题,好像很麻烦,我就不走这条路了.
2.修改系统函数代码,如果有检测,会弹出警告,此时就要改变修改位置,比如双机调试的inlinehook.


ULONG DbgkDebugObjectTypeAddr = 0;
POBJECT_TYPE DbgkDebugObjectType = NULL, MyDbgkDebugObjectType = NULL;
OBJECT_TYPE_INITIALIZER ObjectTypeInitializer;
BOOLEAN bEditDbgkDebugObjectType = FALSE;

BOOLEAN CreateMyDbgkDebugObjectType()
{
    ULONG NtDebugActiveProcess;
    UNICODE_STRING MyObjectTypeName;

    NtDebugActiveProcess = GetSSDTFunctionAddr(SysFuncIdx.NtDebugActiveProcess);
    DbgkDebugObjectTypeAddr = *(PULONG)(NtDebugActiveProcess + 0x5a + 2);
    KdPrint(("DbgkDebugObjectTypeAddr: 0x%8x\n", DbgkDebugObjectTypeAddr)); //8055a540
    if (DbgkDebugObjectTypeAddr == 0)
    {
        KdPrint(("DbgkDebugObjectTypeAddr == 0!"));
        return FALSE;
    }
    DbgkDebugObjectType = (POBJECT_TYPE)(*(PULONG)DbgkDebugObjectTypeAddr);
    KdPrint(("DbgkDebugObjectType: 0x%8x\n", DbgkDebugObjectType)); //863bb040
    KdPrint(("DbgkDebugObjectType->Name: %ws\n", DbgkDebugObjectType->Name.Buffer));
    KdPrint(("TypeInfo.GenericMapping.GenericRead: 0x%08x\n", DbgkDebugObjectType->TypeInfo.GenericMapping.GenericRead)); //00020001
    KdPrint(("TypeInfo.GenericMapping.GenericWrite: 0x%08x\n", DbgkDebugObjectType->TypeInfo.GenericMapping.GenericWrite)); //00020002
    KdPrint(("TypeInfo.GenericMapping.GenericExecute: 0x%08x\n", DbgkDebugObjectType->TypeInfo.GenericMapping.GenericExecute)); //00120000
    KdPrint(("TypeInfo.GenericMapping.GenericAll: 0x%08x\n", DbgkDebugObjectType->TypeInfo.GenericMapping.GenericAll)); //001f000f
    KdPrint(("TypeInfo.ValidAccessMask: 0x%08x\n", DbgkDebugObjectType->TypeInfo.ValidAccessMask)); //001f000f   
    if (wcscmp(DbgkDebugObjectType->Name.Buffer, L"MyDebugObject") == 0)
    {
        KdPrint(("已经修改为MyDebugObject.\n"));
        return FALSE;
    }

    RtlCopyMemory(&ObjectTypeInitializer, &DbgkDebugObjectType->TypeInfo, sizeof(ObjectTypeInitializer));
    if (DbgkDebugObjectType->TypeInfo.ValidAccessMask == 0)
    {
        KdPrint(("DbgkDebugObjectType->TypeInfo.ValidAccessMask被清零,开始恢复.\n"));
        ObjectTypeInitializer.GenericMapping.GenericRead = 0x00020001;
        ObjectTypeInitializer.GenericMapping.GenericWrite = 0x00020002;
        ObjectTypeInitializer.GenericMapping.GenericExecute = 0x00120000;
        ObjectTypeInitializer.GenericMapping.GenericAll = 0x001f000f;
        ObjectTypeInitializer.ValidAccessMask = 0x001f000f;
    }
    RtlInitUnicodeString(&MyObjectTypeName, L"MyDebugObject");
    return (STATUS_SUCCESS == ObCreateObjectType(&MyObjectTypeName, &ObjectTypeInitializer, (PSECURITY_DESCRIPTOR)NULL, &MyDbgkDebugObjectType));

    //0: kd> uf nt!NtDebugActiveProcess
    //nt!NtDebugActiveProcess:
    //80644cb2 8bff            mov     edi,edi
    //80644cb4 55              push    ebp
    //80644cb5 8bec            mov     ebp,esp
    //...
    //nt!NtDebugActiveProcess+0x51:
    //80644d03 6a00            push    0
    //80644d05 8d4508          lea     eax,[ebp+8]
    //80644d08 50              push    eax
    //80644d09 ff75fc          push    dword ptr [ebp-4]
    //80644d0c ff3540a55580    push    dword ptr [nt!DbgkDebugObjectType (8055a540)]
    //80644d12 6a02            push    2
    //80644d14 ff750c          push    dword ptr [ebp+0Ch]
    //80644d17 e8ee77f7ff      call    nt!ObReferenceObjectByHandle (805bc50a)
}

VOID EditDbgkDebugObjectType()
{
    if (bEditDbgkDebugObjectType)
        return;
    if (CreateMyDbgkDebugObjectType())
    {
        WPOFF();
        *(PULONG)DbgkDebugObjectTypeAddr = (ULONG)MyDbgkDebugObjectType;
        WPON();
        bEditDbgkDebugObjectType = TRUE;
    }

    //lkd> dd nt!DbgkDebugObjectType
    //8055a540  863bb040 00000000 00000000 00000000

    //加载tp前:
    //0: kd> dd 863bb040+68
    //863bb0a8  00020001 00020002 00120000 001f000f
    //863bb0b8  001f000f 00000001 00000000 00000000

    //加载tp后:
    //0: kd> dd 863bb040+68
    //863bb0a8  00000000 00000000 00000000 00000000
    //863bb0b8  00000000 00000001 00000000 00000000
}

VOID UnEditDbgkDebugObjectType()
{
    if (!bEditDbgkDebugObjectType)
        return;
    WPOFF();
    *(PULONG)DbgkDebugObjectTypeAddr = (ULONG)DbgkDebugObjectType;
    WPON();
    ObfDereferenceObject(MyDbgkDebugObjectType);
    bEditDbgkDebugObjectType = FALSE;
}