驱动开发：内核监控FileObject文件回调

标签：elements struct bytes OB 内核监控 sizeof fileo FileObject

本篇文章与上一篇文章`《驱动开发：内核注册并监控对象回调》`所使用的方式是一样的都是使用`ObRegisterCallbacks`注册回调事件，只不过上一篇博文中`LyShark`将回调结构体`OB_OPERATION_REGISTRATION`中的`ObjectType`填充为了`PsProcessType`和`PsThreadType`格式从而实现监控进程与线程，本章我们需要将该结构填充为`IoFileObjectType`以此来实现对文件的监控，文件过滤驱动不仅仅可以用来监控文件的打开，还可以用它实现对文件的保护，一旦驱动加载则文件是不可被删除和改动的。

本篇文章与上一篇文章《驱动开发：内核注册并监控对象回调》所使用的方式是一样的都是使用ObRegisterCallbacks注册回调事件，只不过上一篇博文中LyShark将回调结构体OB_OPERATION_REGISTRATION中的ObjectType填充为了PsProcessType和PsThreadType格式从而实现监控进程与线程，本章我们需要将该结构填充为IoFileObjectType以此来实现对文件的监控，文件过滤驱动不仅仅可以用来监控文件的打开，还可以用它实现对文件的保护，一旦驱动加载则文件是不可被删除和改动的。

与进程线程回调有少许的不同，文件回调需要开启驱动的TypeInfo.SupportsObjectCallbacks开关，并定义一些微软结构，如下是我们所需要的公开结构体，可在微软官方或WinDBG中获取到最新的，将其保存为lyshark.h方便后期引用。

// 署名权
// right to sign one's name on a piece of work
// PowerBy: LyShark
// Email: [email protected]
#include <ntddk.h>
#include <ntstrsafe.h>

typedef struct _CALLBACK_ENTRY
{
  LIST_ENTRY CallbackList;
  OB_OPERATION  Operations;
  ULONG Active;
  PVOID Handle;
  POBJECT_TYPE ObjectType;
  POB_PRE_OPERATION_CALLBACK  PreOperation;
  POB_POST_OPERATION_CALLBACK PostOperation;
  ULONG unknown;
} CALLBACK_ENTRY, *PCALLBACK_ENTRY;

typedef struct _LDR_DATA                         // 24 elements, 0xE0 bytes (sizeof)
{
  /*0x000*/     struct _LIST_ENTRY InLoadOrderLinks;                     // 2 elements, 0x10 bytes (sizeof)
  /*0x010*/     struct _LIST_ENTRY InMemoryOrderLinks;                   // 2 elements, 0x10 bytes (sizeof)
  /*0x020*/     struct _LIST_ENTRY InInitializationOrderLinks;           // 2 elements, 0x10 bytes (sizeof)
  /*0x030*/     VOID*        DllBase;
  /*0x038*/     VOID*        EntryPoint;
  /*0x040*/     ULONG32      SizeOfImage;
  /*0x044*/     UINT8        _PADDING0_[0x4];
  /*0x048*/     struct _UNICODE_STRING FullDllName;                      // 3 elements, 0x10 bytes (sizeof)
  /*0x058*/     struct _UNICODE_STRING BaseDllName;                      // 3 elements, 0x10 bytes (sizeof)
  /*0x068*/     ULONG32      Flags;
  /*0x06C*/     UINT16       LoadCount;
  /*0x06E*/     UINT16       TlsIndex;
  union                                                    // 2 elements, 0x10 bytes (sizeof)
  {
    /*0x070*/         struct _LIST_ENTRY HashLinks;                        // 2 elements, 0x10 bytes (sizeof)
    struct                                               // 2 elements, 0x10 bytes (sizeof)
    {
      /*0x070*/             VOID*        SectionPointer;
      /*0x078*/             ULONG32      CheckSum;
      /*0x07C*/             UINT8        _PADDING1_[0x4];
    };
  };
  union                                                    // 2 elements, 0x8 bytes (sizeof)
  {
    /*0x080*/         ULONG32      TimeDateStamp;
    /*0x080*/         VOID*        LoadedImports;
  };
  /*0x088*/     struct _ACTIVATION_CONTEXT* EntryPointActivationContext;
  /*0x090*/     VOID*        PatchInformation;
  /*0x098*/     struct _LIST_ENTRY ForwarderLinks;                       // 2 elements, 0x10 bytes (sizeof)
  /*0x0A8*/     struct _LIST_ENTRY ServiceTagLinks;                      // 2 elements, 0x10 bytes (sizeof)
  /*0x0B8*/     struct _LIST_ENTRY StaticLinks;                          // 2 elements, 0x10 bytes (sizeof)
  /*0x0C8*/     VOID*        ContextInformation;
  /*0x0D0*/     UINT64       OriginalBase;
  /*0x0D8*/     union _LARGE_INTEGER LoadTime;                           // 4 elements, 0x8 bytes (sizeof)
}LDR_DATA, *PLDR_DATA;

typedef struct _OBJECT_TYPE_INITIALIZER                                                                                                                                         // 25 elements, 0x70 bytes (sizeof)
{
  /*0x000*/     UINT16       Length;
  union                                                                                                                                                                       // 2 elements, 0x1 bytes (sizeof)
  {
    /*0x002*/         UINT8        ObjectTypeFlags;
    struct                                                                                                                                                                  // 7 elements, 0x1 bytes (sizeof)
    {
      /*0x002*/             UINT8        CaseInsensitive : 1;                                                                                                                                   // 0 BitPosition
      /*0x002*/             UINT8        UnnamedObjectsOnly : 1;                                                                                                                                // 1 BitPosition
      /*0x002*/             UINT8        UseDefaultObject : 1;                                                                                                                                  // 2 BitPosition
      /*0x002*/             UINT8        SecurityRequired : 1;                                                                                                                                  // 3 BitPosition
      /*0x002*/             UINT8        MaintainHandleCount : 1;                                                                                                                               // 4 BitPosition
      /*0x002*/             UINT8        MaintainTypeList : 1;                                                                                                                                  // 5 BitPosition
      /*0x002*/             UINT8        SupportsObjectCallbacks : 1;                                                                                                                           // 6 BitPosition
    };
  };
  /*0x004*/     ULONG32      ObjectTypeCode;
  /*0x008*/     ULONG32      InvalidAttributes;
  /*0x00C*/     struct _GENERIC_MAPPING GenericMapping;                                                                                                                                     // 4 elements, 0x10 bytes (sizeof)
  /*0x01C*/     ULONG32      ValidAccessMask;
  /*0x020*/     ULONG32      RetainAccess;
  /*0x024*/     enum _POOL_TYPE PoolType;
  /*0x028*/     ULONG32      DefaultPagedPoolCharge;
  /*0x02C*/     ULONG32      DefaultNonPagedPoolCharge;
  /*0x030*/     PVOID DumpProcedure;
  /*0x038*/     PVOID OpenProcedure;
  /*0x040*/     PVOID CloseProcedure;
  /*0x048*/     PVOID DeleteProcedure;
  /*0x050*/     PVOID ParseProcedure;
  /*0x058*/     PVOID SecurityProcedure;
  /*0x060*/     PVOID QueryNameProcedure;
  /*0x068*/     PVOID OkayToCloseProcedure;
}OBJECT_TYPE_INITIALIZER, *POBJECT_TYPE_INITIALIZER;

typedef struct _EX_PUSH_LOCK                 // 7 elements, 0x8 bytes (sizeof)
{
  union                                    // 3 elements, 0x8 bytes (sizeof)
  {
    struct                               // 5 elements, 0x8 bytes (sizeof)
    {
      /*0x000*/             UINT64       Locked : 1;         // 0 BitPosition
      /*0x000*/             UINT64       Waiting : 1;        // 1 BitPosition
      /*0x000*/             UINT64       Waking : 1;         // 2 BitPosition
      /*0x000*/             UINT64       MultipleShared : 1; // 3 BitPosition
      /*0x000*/             UINT64       Shared : 60;        // 4 BitPosition
    };
    /*0x000*/         UINT64       Value;
    /*0x000*/         VOID*        Ptr;
  };
}EX_PUSH_LOCK, *PEX_PUSH_LOCK;

typedef struct _MY_OBJECT_TYPE                   // 12 elements, 0xD0 bytes (sizeof)
{
  /*0x000*/     struct _LIST_ENTRY TypeList;              // 2 elements, 0x10 bytes (sizeof)
  /*0x010*/     struct _UNICODE_STRING Name;              // 3 elements, 0x10 bytes (sizeof)
  /*0x020*/     VOID*        DefaultObject;
  /*0x028*/     UINT8        Index;
  /*0x029*/     UINT8        _PADDING0_[0x3];
  /*0x02C*/     ULONG32      TotalNumberOfObjects;
  /*0x030*/     ULONG32      TotalNumberOfHandles;
  /*0x034*/     ULONG32      HighWaterNumberOfObjects;
  /*0x038*/     ULONG32      HighWaterNumberOfHandles;
  /*0x03C*/     UINT8        _PADDING1_[0x4];
  /*0x040*/     struct _OBJECT_TYPE_INITIALIZER TypeInfo; // 25 elements, 0x70 bytes (sizeof)
  /*0x0B0*/     struct _EX_PUSH_LOCK TypeLock;            // 7 elements, 0x8 bytes (sizeof)
  /*0x0B8*/     ULONG32      Key;
  /*0x0BC*/     UINT8        _PADDING2_[0x4];
  /*0x0C0*/     struct _LIST_ENTRY CallbackList;          // 2 elements, 0x10 bytes (sizeof)
}MY_OBJECT_TYPE, *PMY_OBJECT_TYPE;

对于开启了TypeInfo.SupportsObjectCallbacks属性的驱动来说自然就支持文件路径转换，当系统中有文件被加载则自动执行LySharkFileObjectpreCall回调事件，过滤掉无效路径后即可直接输出，完整代码如下所示；

// 署名权
// right to sign one's name on a piece of work
// PowerBy: LyShark
// Email: [email protected]

#include "lyshark.h"

PVOID obHandle;
DRIVER_INITIALIZE DriverEntry;

// 文件回调
OB_PREOP_CALLBACK_STATUS LySharkFileObjectpreCall(PVOID RegistrationContext, POB_PRE_OPERATION_INFORMATION OperationInformation)
{
  UNICODE_STRING DosName;
  PFILE_OBJECT fileo = OperationInformation->Object;
  HANDLE CurrentProcessId = PsGetCurrentProcessId();
  UNREFERENCED_PARAMETER(RegistrationContext);

  if (OperationInformation->ObjectType != *IoFileObjectType)
  {
    return OB_PREOP_SUCCESS;
  }

  // 过滤无效指针
  if (fileo->FileName.Buffer == NULL || 
    !MmIsAddressValid(fileo->FileName.Buffer) || 
    fileo->DeviceObject == NULL || 
    !MmIsAddressValid(fileo->DeviceObject))
  {
    return OB_PREOP_SUCCESS;
  }

  // 过滤无效路径
  if (!_wcsicmp(fileo->FileName.Buffer, L"\\Endpoint") || 
    !_wcsicmp(fileo->FileName.Buffer, L"?") || 
    !_wcsicmp(fileo->FileName.Buffer, L"\\.\\.") || 
    !_wcsicmp(fileo->FileName.Buffer, L"\\"))
  {
    return OB_PREOP_SUCCESS;
  }

  // 将对象转为DOS路径
  RtlVolumeDeviceToDosName(fileo->DeviceObject, &DosName);
  DbgPrint("[LyShark] 进程PID = %ld | 文件路径 = %wZ%wZ \n", (ULONG64)CurrentProcessId, &DosName, &fileo->FileName);

  return OB_PREOP_SUCCESS;
}

VOID EnableObType(POBJECT_TYPE ObjectType)
{
  PMY_OBJECT_TYPE myobtype = (PMY_OBJECT_TYPE)ObjectType;
  myobtype->TypeInfo.SupportsObjectCallbacks = 1;
}

VOID UnDriver(PDRIVER_OBJECT driver)
{
  UNREFERENCED_PARAMETER(driver);
  ObUnRegisterCallbacks(obHandle);
}

NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
  NTSTATUS status = STATUS_SUCCESS;
  PLDR_DATA ldr;

  DbgPrint("hello lyshark.com \n");

  OB_CALLBACK_REGISTRATION obRegFileCallBack;
  OB_OPERATION_REGISTRATION opRegFileCallBack;

  // enable IoFileObjectType
  EnableObType(*IoFileObjectType);

  // bypass MmVerifyCallbackFunction
  ldr = (PLDR_DATA)Driver->DriverSection;
  ldr->Flags |= 0x20;

  // 初始化回调
  memset(&obRegFileCallBack, 0, sizeof(obRegFileCallBack));
  obRegFileCallBack.Version = ObGetFilterVersion();
  obRegFileCallBack.OperationRegistrationCount = 1;
  obRegFileCallBack.RegistrationContext = NULL;
  RtlInitUnicodeString(&obRegFileCallBack.Altitude, L"321000");
  obRegFileCallBack.OperationRegistration = &opRegFileCallBack;

  memset(&opRegFileCallBack, 0, sizeof(opRegFileCallBack));
  opRegFileCallBack.ObjectType = IoFileObjectType;
  opRegFileCallBack.Operations = OB_OPERATION_HANDLE_CREATE | OB_OPERATION_HANDLE_DUPLICATE;
  opRegFileCallBack.PreOperation = (POB_PRE_OPERATION_CALLBACK)&LySharkFileObjectpreCall;

  status = ObRegisterCallbacks(&obRegFileCallBack, &obHandle);
  if (!NT_SUCCESS(status))
  {
    DbgPrint("注册回调错误 \n");
    status = STATUS_UNSUCCESSFUL;
  }

  UNREFERENCED_PARAMETER(RegistryPath);
  Driver->DriverUnload = &UnDriver;
  return status;
}

运行这个驱动程序，当系统中有新文件被加载时则自动输出该文件所属进程PID以及该文件的详细路径。

驱动开发：内核监控FileObject文件回调_Windows 内核驱动开发

至于如何阻止打开一个文件其实与《驱动开发：内核注册并监控对象回调》文章中使用的方法是一致的，首先判断OperationInformation->Operation是不是OB_OPERATION_HANDLE_CREATE或OB_OPERATION_HANDLE_DUPLICATE如果是，则直接设置Parameters->CreateHandleInformation.DesiredAccess为0直接拒绝加载。

// 文件回调
OB_PREOP_CALLBACK_STATUS LySharkFileObjectpreCall(PVOID RegistrationContext, POB_PRE_OPERATION_INFORMATION OperationInformation)
{
  UNICODE_STRING DosName;
  PFILE_OBJECT fileo = OperationInformation->Object;
  HANDLE CurrentProcessId = PsGetCurrentProcessId();
  UNREFERENCED_PARAMETER(RegistrationContext);

  if (OperationInformation->ObjectType != *IoFileObjectType)
  {
    return OB_PREOP_SUCCESS;
  }

  // 过滤无效指针
  if (fileo->FileName.Buffer == NULL || 
    !MmIsAddressValid(fileo->FileName.Buffer) || 
    fileo->DeviceObject == NULL || 
    !MmIsAddressValid(fileo->DeviceObject))
  {
    return OB_PREOP_SUCCESS;
  }

  // 过滤无效路径
  if (!_wcsicmp(fileo->FileName.Buffer, L"\\Endpoint") || 
    !_wcsicmp(fileo->FileName.Buffer, L"?") || 
    !_wcsicmp(fileo->FileName.Buffer, L"\\.\\.") || 
    !_wcsicmp(fileo->FileName.Buffer, L"\\"))
  {
    return OB_PREOP_SUCCESS;
  }

  // 阻止打开lyshark_com.txt文本
  if (wcsstr(_wcslwr(fileo->FileName.Buffer), L"lyshark_com.txt"))
  {
    if (OperationInformation->Operation == OB_OPERATION_HANDLE_CREATE)
    {
      OperationInformation->Parameters->CreateHandleInformation.DesiredAccess = 0;
    }
    if (OperationInformation->Operation == OB_OPERATION_HANDLE_DUPLICATE)
    {
      OperationInformation->Parameters->DuplicateHandleInformation.DesiredAccess = 0;
    }
    DbgPrint("[LyShark] 已拦截 lyshark_com 文件打开 \n");
  }

  return OB_PREOP_SUCCESS;
}

运行修改后的驱动程序，然后尝试打开lyshark_com.txt则会提示系统找不到指定文件。

驱动开发：内核监控FileObject文件回调_#include_02

文章作者：lyshark (王瑞)
版权声明：本博客文章与代码均为学习时整理的笔记，文章 [均为原创] 作品，转载请 [添加出处] ，您添加出处是我创作的动力！

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标签：elements,struct,bytes,OB,内核,监控,sizeof,fileo,FileObject
From： https://blog.51cto.com/lyshark/5807433

驱动开发：内核监控FileObject文件回调

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