本篇文章與上一篇文章《驅動開發:核心註冊並監控物件回撥》
所使用的方式是一樣的都是使用ObRegisterCallbacks
註冊回撥事件,只不過上一篇博文中LyShark
將回撥結構體OB_OPERATION_REGISTRATION
中的ObjectType
填充為了PsProcessType
和PsThreadType
格式從而實現監控程序與執行緒,本章我們需要將該結構填充為IoFileObjectType
以此來實現對檔案的監控,檔案過濾驅動不僅僅可以用來監控檔案的開啟,還可以用它實現對檔案的保護,一旦驅動載入則檔案是不可被刪除和改動的。
與程序執行緒回撥有少許的不同,檔案回撥需要開啟驅動的TypeInfo.SupportsObjectCallbacks
開關,並定義一些微軟結構,如下是我們所需要的公開結構體,可在微軟官方或WinDBG中獲取到最新的,將其儲存為lyshark.h
方便後期參照。
// 署名權
// 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;
對於開啟了TypeInfo.SupportsObjectCallbacks
屬性的驅動來說自然就支援檔案路徑轉換,當系統中有檔案被載入則自動執行LySharkFileObjectpreCall
回撥事件,過濾掉無效路徑後即可直接輸出,完整程式碼如下所示;
// 署名權
// right to sign one's name on a piece of work
// PowerBy: LyShark
// Email: [email protected]
#include "lyshark.h"
PVOID obHandle;
DRIVER_INITIALIZE DriverEntry;
// 檔案回撥
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;
}
// 過濾無效指標
if (fileo->FileName.Buffer == NULL ||
!MmIsAddressValid(fileo->FileName.Buffer) ||
fileo->DeviceObject == NULL ||
!MmIsAddressValid(fileo->DeviceObject))
{
return OB_PREOP_SUCCESS;
}
// 過濾無效路徑
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;
}
// 將物件轉為DOS路徑
RtlVolumeDeviceToDosName(fileo->DeviceObject, &DosName);
DbgPrint("[LyShark] 程序PID = %ld | 檔案路徑 = %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;
// 初始化回撥
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("註冊回撥錯誤 \n");
status = STATUS_UNSUCCESSFUL;
}
UNREFERENCED_PARAMETER(RegistryPath);
Driver->DriverUnload = &UnDriver;
return status;
}
執行這個驅動程式,當系統中有新檔案被載入時則自動輸出該檔案所屬程序PID以及該檔案的詳細路徑。
至於如何阻止開啟一個檔案其實與《驅動開發:核心註冊並監控物件回撥》
文章中使用的方法是一致的,首先判斷OperationInformation->Operation
是不是OB_OPERATION_HANDLE_CREATE
或OB_OPERATION_HANDLE_DUPLICATE
如果是,則直接設定Parameters->CreateHandleInformation.DesiredAccess
為0直接拒絕載入。
// 檔案回撥
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;
}
// 過濾無效指標
if (fileo->FileName.Buffer == NULL ||
!MmIsAddressValid(fileo->FileName.Buffer) ||
fileo->DeviceObject == NULL ||
!MmIsAddressValid(fileo->DeviceObject))
{
return OB_PREOP_SUCCESS;
}
// 過濾無效路徑
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;
}
// 阻止開啟lyshark_com.txt文字
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] 已攔截 lyshark_com 檔案開啟 \n");
}
return OB_PREOP_SUCCESS;
}
執行修改後的驅動程式,然後嘗試開啟lyshark_com.txt
則會提示系統找不到指定檔案。