一个简单的Object Hook的例子（win7 32bit）

Object Hook简单的来说就是Hook对象，这里拿看雪上的一个例子，因为是在win7 32位上的，有些地方做了些修改。

_OBJECT_HEADER：

kd> dt _OBJECT_HEADER
nt!_OBJECT_HEADER
   +0×000 PointerCount     : Int4B
   +0×004 HandleCount      : Int4B
   +0×004 NextToFree       : Ptr32 Void
   +0×008 Lock             : _EX_PUSH_LOCK
   +0x00c TypeIndex        : UChar
   +0x00d TraceFlags       : UChar
   +0x00e InfoMask         : UChar
   +0x00f Flags            : UChar
   +0×010 ObjectCreateInfo : Ptr32 _OBJECT_CREATE_INFORMATION
   +0×010 QuotaBlockCharged : Ptr32 Void
   +0×014 SecurityDescriptor : Ptr32 Void
   +0×018 Body             : _QUAD

在Win7 Object_Header之TypeIndex解析已经说了怎么通过TypeIndex得到对象类型：

_OBJECT_TYPE：

kd> dt _OBJECT_TYPE
nt!_OBJECT_TYPE
   +0×000 TypeList         : _LIST_ENTRY
   +0×008 Name             : _UNICODE_STRING
   +0×010 DefaultObject    : Ptr32 Void
   +0×014 Index            : UChar
   +0×018 TotalNumberOfObjects : Uint4B
   +0x01c TotalNumberOfHandles : Uint4B
   +0×020 HighWaterNumberOfObjects : Uint4B
   +0×024 HighWaterNumberOfHandles : Uint4B
   +0×028 TypeInfo         : _OBJECT_TYPE_INITIALIZER
   +0×078 TypeLock         : _EX_PUSH_LOCK
   +0x07c Key              : Uint4B
   +0×080 CallbackList     : _LIST_ENTRY

对象类型结构主要是创建对象类型，比如*IoFileObjectType, *PsProcessType, *PsThreadType 这些。

系统初始化的时候第一个创建的对象类型结构就是TYPE结构，生成对象目录ObjectTypes 其后面的对象类型直接挂在这个目录上

比如对象类型 ObjectTypesFile 或者设备类型 ObjectTypesDevice

最重要的是下面这个结构：

kd> dt _OBJECT_TYPE_INITIALIZER
nt!_OBJECT_TYPE_INITIALIZER
   +0×000 Length           : Uint2B
   +0×002 ObjectTypeFlags : UChar
   +0×002 CaseInsensitive : Pos 0, 1 Bit
   +0×002 UnnamedObjectsOnly : Pos 1, 1 Bit
   +0×002 UseDefaultObject : Pos 2, 1 Bit
   +0×002 SecurityRequired : Pos 3, 1 Bit
   +0×002 MaintainHandleCount : Pos 4, 1 Bit
   +0×002 MaintainTypeList : Pos 5, 1 Bit
   +0×002 SupportsObjectCallbacks : Pos 6, 1 Bit
   +0×004 ObjectTypeCode   : Uint4B
   +0×008 InvalidAttributes : Uint4B
   +0x00c GenericMapping   : _GENERIC_MAPPING
   +0x01c ValidAccessMask : Uint4B
   +0×020 RetainAccess     : Uint4B
   +0×024 PoolType         : _POOL_TYPE
   +0×028 DefaultPagedPoolCharge : Uint4B
   +0x02c DefaultNonPagedPoolCharge : Uint4B
   +0×030 DumpProcedure    : Ptr32     void
   +0×034 OpenProcedure    : Ptr32     long
   +0×038 CloseProcedure   : Ptr32     void
   +0x03c DeleteProcedure : Ptr32     void
   +0×040 ParseProcedure   : Ptr32     long
   +0×044 SecurityProcedure : Ptr32     long
   +0×048 QueryNameProcedure : Ptr32     long
   +0x04c OkayToCloseProcedure : Ptr32     unsigned char

后面这几个函数决定对象的一些操作，例如打开、创建、删除，不同对象类型（OBJECT_TYPE）的操作也不同，所以要清楚知道对象是什么类型。

当你调用NtCreateFile->IoCreateFile->ObOpenObjectByName->ObpLookupObjectName->IopParseFile->IopParseDevice
IopParseFile最终也会调用IopParseDevice
ObjectHook其实就是比如你要HOOK 创建打开就是OBJECT_TYPE_INITIALIZER->ParseProcedure。

代码如下：

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#include <ntddk.h>

typedef PULONG (NTAPI *OBGETOBJECTTYPE)(PVOID);
OBGETOBJECTTYPE OBGetObjectType;

typedef struct _OBJECT_TYPE_INITIALIZER {
USHORT Length ;
UCHAR ObjectTypeFlags ;
UCHAR CaseInsensitive ;
UCHAR UnnamedObjectsOnly ;
UCHAR UseDefaultObject ;
UCHAR SecurityRequired ;
UCHAR MaintainHandleCount ;
UCHAR MaintainTypeList ;
UCHAR SupportsObjectCallbacks ;
UCHAR CacheAligned ;
ULONG ObjectTypeCode ;
BOOLEAN InvalidAttributes ;
GENERIC_MAPPING GenericMapping ;
BOOLEAN ValidAccessMask ;
BOOLEAN RetainAccess ;
POOL_TYPE PoolType ;
BOOLEAN DefaultPagedPoolCharge ;
BOOLEAN DefaultNonPagedPoolCharge ;
PVOID DumpProcedure ;
ULONG OpenProcedure ;
PVOID CloseProcedure ;
PVOID DeleteProcedure ;
ULONG ParseProcedure ;
ULONG SecurityProcedure;
ULONG QueryNameProcedure;
UCHAR OkayToCloseProcedure ;
} OBJECT_TYPE_INITIALIZER, *POBJECT_TYPE_INITIALIZER;
typedef struct _OBJECT_TYPE {
LIST_ENTRY TypeList;
UNICODE_STRING Name;
PVOID DefaultObject;
ULONG Index;
ULONG TotalNumberOfObjects;
ULONG TotalNumberOfHandles;
ULONG HighWaterNumberOfObjects;
ULONG HighWaterNumberOfHandles;
OBJECT_TYPE_INITIALIZER TypeInfo ;
ULONG TypeLock;
ULONG Key;
LIST_ENTRY CallbackList;
} OBJECT_TYPE, *POBJECT_TYPE;

POBJECT_TYPE pType = NULL;
PVOID OldParseProcedure = NULL;

NTSTATUS NewParseProcedure(IN PVOID ParseObject,
IN PVOID ObjectType,
IN OUT PACCESS_STATE AccessState,
IN KPROCESSOR_MODE AccessMode,
IN ULONG Attributes,
IN OUT PUNICODE_STRING CompleteName,
IN OUT PUNICODE_STRING RemainingName,
IN OUT PVOID Context OPTIONAL,
IN PSECURITY_QUALITY_OF_SERVICE SecurityQos OPTIONAL,
OUT PVOID *Object)
{
NTSTATUS Status;
KdPrint(("object is hook "));
__asm
{
push eax
push Object
push SecurityQos
push Context
push RemainingName
push CompleteName
push Attributes
movzx eax, AccessMode
push eax
push AccessState
push ObjectType
push ParseObject
call OldParseProcedure
mov Status, eax
pop eax
}
return Status;
}
VOID GetObGetObjectTypeAddress()
{
PUCHAR addr;
UNICODE_STRING pslookup;
RtlInitUnicodeString(&pslookup,L"ObGetObjectType");
addr=(PUCHAR)MmGetSystemRoutineAddress(&pslookup);
OBGetObjectType=(OBGETOBJECTTYPE )addr;
}
NTSTATUS Hook()
{
NTSTATUS Status;
HANDLE hFile;
UNICODE_STRING Name;
OBJECT_ATTRIBUTES Attr;
IO_STATUS_BLOCK ioStaBlock;
PVOID pObject = NULL;

RtlInitUnicodeString(&Name,L"\Device\HarddiskVolume1\1.txt"); //C:1.txt
InitializeObjectAttributes(&Attr,&Name,OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE ,
0,NULL);
Status = ZwOpenFile(&hFile,GENERIC_ALL,&Attr,&ioStaBlock,
0,FILE_NON_DIRECTORY_FILE);
if (!NT_SUCCESS(Status))
{
KdPrint(("File is Null "));
return Status;
}

Status = ObReferenceObjectByHandle(hFile,GENERIC_ALL,NULL,KernelMode,&pObject,NULL);
if (!NT_SUCCESS(Status))
{
KdPrint(("Object is Null "));
return Status;
}

KdPrint(("pobject is %08X ",pObject));
//win7 获取objecttype更加方便了。。。
pType = (POBJECT_TYPE)OBGetObjectType(pObject);

KdPrint(("pType is %08X ",pType));
OldParseProcedure = pType->TypeInfo.ParseProcedure;
KdPrint(("OldParseProcedure addrs is %08X ",OldParseProcedure));
//这里最好检查一下OldParseProcedure,是否为0

pType->TypeInfo.ParseProcedure = NewParseProcedure;//hook 因为object原本就是是可写的，所以不用特意去除内存保护
Status = ZwClose(hFile);
return Status;
}

NTSTATUS DriverEntry(PDRIVER_OBJECT DriverObject,PUNICODE_STRING RegistryPath)
{
NTSTATUS Status = STATUS_SUCCESS;
GetObGetObjectTypeAddress();
Status=Hook();
return Status;
}

效果：

本文链接：http://www.blogfshare.com/object-hook.html

object_header地址=_EPROCESS地址

jpg 改 rar