在笔者上一篇文章《内核枚举进程与线程ObCall回调》
简单介绍了如何枚举系统中已经存在的进程与线程
回调,本章LyShark
将通过对象回调实现对进程线程的句柄
监控,在内核中提供了ObRegisterCallbacks
回调,使用这个内核回调
函数,可注册一个对象
回调,不过目前该函数只能
监控进程与线程句柄操作,通过监控进程或线程句柄,可实现保护指定进程线程不被终止的目的。
ObRegisterCallbacks是Windows操作系统提供的一个内核API函数,它允许开发者注册一个回调函数,用于监控对象的创建、打开、关闭和删除等事件。对象可以是文件、目录、进程、线程、注册表键等等。
当操作系统创建、打开、关闭或删除一个对象时,它会触发注册的回调函数,然后在回调函数中调用开发者定义的代码。开发者可以在回调函数中执行自定义的逻辑,例如记录日志、过滤敏感数据、或者阻止某些操作。
ObRegisterCallbacks函数提供了多个回调函数的注册,这些回调函数包括:
需要注意的是,注册回调函数需要开发者有一定的内核开发经验,并且需要遵守一些约束条件,例如不能阻塞或挂起对象的操作,不能调用一些内核API函数等。
内核注册并监控对象回调ObRegisterCallbacks在安全软件、系统监控和调试工具等领域有着广泛的应用。开发者可以利用这个机制来监控系统对象的使用情况,以保护系统安全。
由于目前对象回调只能监控进程与线程,而这个监控是通过ObjectType
这么一个成员控制的,如果成员是PsProcessType
则代表监控进程,反之PsThreadType
则是监控线程,无论监控进程还是线程都调用ObRegisterCallbacks
这个函数来完成注册。
函数ObRegisterCallbacks
其微软对他的定义是这样的,用户传入OB_OPERATION_REGISTRATION
结构,以及OB_CALLBACK_REGISTRATION
回调结构,其中PreOperation
则是传入的回调函数,也是最重要的,其次是ObjectType
指定成进程回调。
NTSTATUS ObRegisterCallbacks(
[in] POB_CALLBACK_REGISTRATION CallbackRegistration,
[out] PVOID *RegistrationHandle
);
首先来实现一个检测的案例,注册一个进程回调对象MyLySharkComObjectCallBack
,通过ObRegisterCallbacks
注册的回调只需要传入一个填充好的OB_CALLBACK_REGISTRATION
回调结构体,以及一个全局句柄即可,这个全局句柄的作用仅仅只是在程序结束时,调用ObUnRegisterCallbacks
卸载监控而已,实现代码如下所示。
#include <ntddk.h>
#include <ntstrsafe.h>
PVOID Globle_Object_Handle;
// 绕过签名检测
void BypassCheckSign(PDRIVER_OBJECT pDriverObj)
{
typedef struct _LDR_DATA
{
struct _LIST_ENTRY InLoadOrderLinks;
struct _LIST_ENTRY InMemoryOrderLinks;
struct _LIST_ENTRY InInitializationOrderLinks;
VOID* DllBase;
VOID* EntryPoint;
ULONG32 SizeOfImage;
UINT8 _PADDING0_[0x4];
struct _UNICODE_STRING FullDllName;
struct _UNICODE_STRING BaseDllName;
ULONG32 Flags;
}LDR_DATA, *PLDR_DATA;
PLDR_DATA ldr;
ldr = (PLDR_DATA)(pDriverObj->DriverSection);
ldr->Flags |= 0x20;
}
// 自定义回调
OB_PREOP_CALLBACK_STATUS MyLySharkComObjectCallBack(PVOID RegistrationContext, POB_PRE_OPERATION_INFORMATION OperationInformation)
{
DbgPrint("[lyshark] 执行回调函数... \n");
return STATUS_SUCCESS;
}
VOID UnDriver(PDRIVER_OBJECT driver)
{
ObUnRegisterCallbacks(Globle_Object_Handle);
DbgPrint("回调卸载完成... \n");
}
NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
DbgPrint("hello lyshark \n");
BypassCheckSign(Driver);
OB_OPERATION_REGISTRATION Base; // 回调函数结构体
OB_CALLBACK_REGISTRATION CallbackReg; // 回调函数
CallbackReg.RegistrationContext = NULL; // 注册上下文(你回调函数返回参数)
CallbackReg.Version = OB_FLT_REGISTRATION_VERSION; // 注册回调版本
CallbackReg.OperationRegistration = &Base; // 回调结构体
CallbackReg.OperationRegistrationCount = 1; // 操作计数(下钩数量)
RtlUnicodeStringInit(&CallbackReg.Altitude, L"600000"); // 长度
Base.ObjectType = PsProcessType; // 进程操作类型.此处为进程操作
Base.Operations = OB_OPERATION_HANDLE_CREATE; // 操作句柄创建
Base.PreOperation = MyLySharkComObjectCallBack; // 你自己的回调函数
Base.PostOperation = NULL;
// 注册回调
if (ObRegisterCallbacks(&CallbackReg, &Globle_Object_Handle))
{
DbgPrint("[lyshark message] 回调注册成功...");
}
Driver->DriverUnload = UnDriver;
return STATUS_SUCCESS;
}
当驱动程序被加载以后,一旦有进程运行则会执行我们自己的MyLySharkComObjectCallBack
回调,而在回调函数内则可以执行任意功能,运行如下所示。
如上所示只是演示基本的回调申请流程,回调函数通常需要包含两个值,其一RegistrationContext
用于标注上下文,其二POB_PRE_OPERATION_INFORMATION
则用于标注进程或者线程创建的信息结构体。
OB_PREOP_CALLBACK_STATUS MyLySharkComObjectCallBack(PVOID RegistrationContext, POB_PRE_OPERATION_INFORMATION OperationInformation)
那么如何实现拦截进程启动
这个功能呢,我们可以在回调函数中写入以下代码进行拦截。
if (pOperationInformation->Operation == OB_OPERATION_HANDLE_CREATE)
{
DbgPrint("lyshark.exe 进程打开 \n");
pOperationInformation->Parameters->CreateHandleInformation.DesiredAccess=0;
if ((pOperationInformation->Parameters->CreateHandleInformation.OriginalDesiredAccess & PROCESS_TERMINATE) == PROCESS_TERMINATE)
{
pOperationInformation->Parameters->CreateHandleInformation.DesiredAccess &= ~PROCESS_TERMINATE;
}
}
拦截进程创建核心代码如下所示。
#include <ntddk.h>
#include <ntstrsafe.h>
#define PROCESS_TERMINATE 0x1
// 导出两个API
NTKERNELAPI PEPROCESS IoThreadToProcess(PETHREAD Thread);
NTKERNELAPI char* PsGetProcessImageFileName(PEPROCESS Process);
// 全局句柄
PVOID Globle_Object_Handle = NULL;
// 绕过签名检测
void BypassCheckSign(PDRIVER_OBJECT pDriverObj)
{
typedef struct _LDR_DATA
{
struct _LIST_ENTRY InLoadOrderLinks;
struct _LIST_ENTRY InMemoryOrderLinks;
struct _LIST_ENTRY InInitializationOrderLinks;
VOID* DllBase;
VOID* EntryPoint;
ULONG32 SizeOfImage;
UINT8 _PADDING0_[0x4];
struct _UNICODE_STRING FullDllName;
struct _UNICODE_STRING BaseDllName;
ULONG32 Flags;
}LDR_DATA, *PLDR_DATA;
PLDR_DATA ldr;
ldr = (PLDR_DATA)(pDriverObj->DriverSection);
ldr->Flags |= 0x20;
}
// 判断是否是需要保护的进程
BOOLEAN CheckProcess(PEPROCESS eprocess)
{
char *Name = PsGetProcessImageFileName(eprocess);
if (!_stricmp("lyshark.exe", Name))
return TRUE;
else
return FALSE;
}
// 进程回调
OB_PREOP_CALLBACK_STATUS MyLySharkProcessObjectCallBack(PVOID RegistrationContext, POB_PRE_OPERATION_INFORMATION pOperationInformation)
{
HANDLE pid;
// 只取出进程回调
if (pOperationInformation->ObjectType != *PsProcessType)
{
return OB_PREOP_SUCCESS;
}
// 得到所有进程的ID
pid = PsGetProcessId((PEPROCESS)pOperationInformation->Object);
// DbgPrint("进程PID= %ld \n", pid);
UNREFERENCED_PARAMETER(RegistrationContext);
// 验证是否是需要的进程
if (CheckProcess((PEPROCESS)pOperationInformation->Object))
{
// 创建句柄
if (pOperationInformation->Operation == OB_OPERATION_HANDLE_CREATE)
{
DbgPrint("lyshark.exe 进程打开事件 \n");
pOperationInformation->Parameters->CreateHandleInformation.DesiredAccess=0;
if ((pOperationInformation->Parameters->CreateHandleInformation.OriginalDesiredAccess & PROCESS_TERMINATE) == PROCESS_TERMINATE)
{
DbgPrint("[LyShark Message] 拦截进程打开 \n");
pOperationInformation->Parameters->CreateHandleInformation.DesiredAccess &= ~PROCESS_TERMINATE;
}
}
// 复制句柄
if (pOperationInformation->Operation == OB_OPERATION_HANDLE_DUPLICATE)
{
DbgPrint("lyshark.exe 进程被关闭 \n");
pOperationInformation->Parameters->DuplicateHandleInformation.DesiredAccess=0;
if ((pOperationInformation->Parameters->DuplicateHandleInformation.OriginalDesiredAccess & PROCESS_TERMINATE) == PROCESS_TERMINATE)
{
pOperationInformation->Parameters->DuplicateHandleInformation.DesiredAccess &= ~PROCESS_TERMINATE;
}
}
}
return OB_PREOP_SUCCESS;
}
VOID UnDriver(PDRIVER_OBJECT driver)
{
ObUnRegisterCallbacks(Globle_Object_Handle);
DbgPrint("回调卸载完成... \n");
}
NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
DbgPrint("hello lyshark \n");
BypassCheckSign(Driver);
OB_OPERATION_REGISTRATION ob_process_callback;
OB_CALLBACK_REGISTRATION op_process_operation;
memset(&ob_process_callback, 0, sizeof(ob_process_callback));
ob_process_callback.ObjectType = PsProcessType;
ob_process_callback.Operations = OB_OPERATION_HANDLE_CREATE | OB_OPERATION_HANDLE_DUPLICATE;
ob_process_callback.PreOperation = MyLySharkProcessObjectCallBack;
ob_process_callback.PostOperation = NULL;
RtlUnicodeStringInit(&op_process_operation.Altitude, L"600000");
op_process_operation.RegistrationContext = NULL;
op_process_operation.Version = OB_FLT_REGISTRATION_VERSION;
op_process_operation.OperationRegistration = &ob_process_callback;
op_process_operation.OperationRegistrationCount = 1;
// 注册进程回调
if (ObRegisterCallbacks(&op_process_operation, &Globle_Object_Handle))
{
DbgPrint("进程回调注册成功...");
}
Driver->DriverUnload = UnDriver;
return STATUS_SUCCESS;
}
加载这个驱动,当有进程被创建时,则首先判断是否是lyshark.exe
如果是则直接禁止打开,也就是终止掉。
同理进程可以被拦截,那么如果增加更多的过滤条件,则线程
同样可以被拦截,拦截线程代码如下所示。
#include <ntddk.h>
#include <ntstrsafe.h>
#define THREAD_TERMINATE2 0x1
// 导出两个API
NTKERNELAPI PEPROCESS IoThreadToProcess(PETHREAD Thread);
NTKERNELAPI char* PsGetProcessImageFileName(PEPROCESS Process);
// 全局句柄
PVOID Globle_Object_Handle = NULL;
// 绕过签名检测
void BypassCheckSign(PDRIVER_OBJECT pDriverObj)
{
typedef struct _LDR_DATA
{
struct _LIST_ENTRY InLoadOrderLinks;
struct _LIST_ENTRY InMemoryOrderLinks;
struct _LIST_ENTRY InInitializationOrderLinks;
VOID* DllBase;
VOID* EntryPoint;
ULONG32 SizeOfImage;
UINT8 _PADDING0_[0x4];
struct _UNICODE_STRING FullDllName;
struct _UNICODE_STRING BaseDllName;
ULONG32 Flags;
}LDR_DATA, *PLDR_DATA;
PLDR_DATA ldr;
ldr = (PLDR_DATA)(pDriverObj->DriverSection);
ldr->Flags |= 0x20;
}
// 判断是否是需要保护的进程
BOOLEAN CheckProcess(PEPROCESS eprocess)
{
char *Name = PsGetProcessImageFileName(eprocess);
if (!_stricmp("lyshark.exe", Name))
return TRUE;
else
return FALSE;
}
// 线程回调
OB_PREOP_CALLBACK_STATUS MyThreadObjectCallBack(PVOID RegistrationContext, POB_PRE_OPERATION_INFORMATION pOperationInformation)
{
PEPROCESS ep;
PETHREAD et;
HANDLE pid;
// 线程过滤
if (pOperationInformation->ObjectType != *PsThreadType)
{
return OB_PREOP_SUCCESS;
}
et = (PETHREAD)pOperationInformation->Object;
ep = IoThreadToProcess(et);
pid = PsGetProcessId(ep);
// DbgPrint("线程PID= %ld | TID= %ld \n", pid, PsGetThreadId(et));
UNREFERENCED_PARAMETER(RegistrationContext);
if (CheckProcess(ep))
{
if (pOperationInformation->Operation == OB_OPERATION_HANDLE_CREATE)
{
pOperationInformation->Parameters->CreateHandleInformation.DesiredAccess=0;
if ((pOperationInformation->Parameters->CreateHandleInformation.OriginalDesiredAccess & THREAD_TERMINATE2) == THREAD_TERMINATE2)
{
DbgPrint("[LyShark] 拦截lyshark.exe进程内 %d 线程创建 \n", PsGetThreadId(et));
pOperationInformation->Parameters->CreateHandleInformation.DesiredAccess &= ~THREAD_TERMINATE2;
}
}
if (pOperationInformation->Operation == OB_OPERATION_HANDLE_DUPLICATE)
{
pOperationInformation->Parameters->DuplicateHandleInformation.DesiredAccess=0;
if ((pOperationInformation->Parameters->DuplicateHandleInformation.OriginalDesiredAccess & THREAD_TERMINATE2) == THREAD_TERMINATE2)
{
pOperationInformation->Parameters->DuplicateHandleInformation.DesiredAccess &= ~THREAD_TERMINATE2;
}
}
}
return OB_PREOP_SUCCESS;
}
VOID UnDriver(PDRIVER_OBJECT driver)
{
ObUnRegisterCallbacks(Globle_Object_Handle);
DbgPrint("回调卸载完成... \n");
}
NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
DbgPrint("hello lyshark \n");
BypassCheckSign(Driver);
OB_OPERATION_REGISTRATION ob_thread_callback;
OB_CALLBACK_REGISTRATION op_thread_operation;
memset(&ob_thread_callback, 0, sizeof(ob_thread_callback));
ob_thread_callback.ObjectType = PsThreadType;
ob_thread_callback.Operations = OB_OPERATION_HANDLE_CREATE | OB_OPERATION_HANDLE_DUPLICATE;
ob_thread_callback.PreOperation = MyThreadObjectCallBack;
ob_thread_callback.PostOperation = NULL;
RtlUnicodeStringInit(&op_thread_operation.Altitude, L"600001");
op_thread_operation.RegistrationContext = NULL;
op_thread_operation.Version = OB_FLT_REGISTRATION_VERSION;
op_thread_operation.OperationRegistration = &ob_thread_callback;
op_thread_operation.OperationRegistrationCount = 1;
// 注册进程回调
if (ObRegisterCallbacks(&op_thread_operation, &Globle_Object_Handle))
{
DbgPrint("进程回调注册成功...");
}
Driver->DriverUnload = UnDriver;
return STATUS_SUCCESS;
}
这段驱动加载后,如果有新线程被创建,则会被拦截并打印输出,效果图如下。