Ring0下的Inline Hook技术详解<\/h1>

前言<\/h2>
Inline Hook是一种直接在目标函数内部修改指令的技术，通过插入跳转或其他指令来实现挂钩功能。与普通Hook（仅修改函数调用地址）相比，Inline Hook更加高级且难以被发现。本文详细讲解在Ring0（内核层）实现Inline Hook的技术原理和实现方法。<\/p>

技术原理<\/h2>

Inline Hook与普通Hook的区别<\/h3>

普通Hook<\/strong>：修改函数的调用地址，指向自定义函数<\/li>

Inline Hook<\/strong>：在原始函数体内修改指令（通常是前几条指令），插入跳转指令<\/li> <\/ul>
实现要点<\/h3>

需要至少5个字节的硬编码空间（用于E8 call或E9 jmp）<\/li>
不能选择涉及全局变量和重定位地址的指令进行修改<\/li>
需要临时关闭内存页保护才能修改内核代码<\/li>
必须保存被覆盖的原始指令以便恢复<\/li> <\/ol>
实现步骤<\/h2>
1. 定位目标函数<\/h3>
以NtOpenFile<\/code>为例，通过以下步骤定位：<\/p>
使用Windbg查找ZwOpenFile<\/code>函数偏移（示例中为0x74）<\/li> 通过SSDT表找到内核函数地址<\/li> 计算NtOpenFile<\/code>的实际地址<\/li> <\/ol> kd> dd KeServiceDescriptorTable kd> dd 80505450 + 74 * 4 kd> u 8057b182 <\/code><\/pre> 2. 准备Hook代码<\/h3> 定义过滤函数<\/h4> char<\/span> *<\/span>p =<\/span> "r0 InlineHook"<\/span>; <\/span><\/span>void<\/span> FilterNtOpenFile<\/span>(char<\/span> *<\/span>p) { <\/span><\/span> KdPrint(("%s <\/span>\r\n<\/span>"<\/span>, p)); <\/span><\/span> KdPrint(("name:%s <\/span>\r\n<\/span>"<\/span>, (char<\/span>*<\/span>)PsGetCurrentProcess() +<\/span> 0x174<\/span>)); <\/span><\/span>} <\/span><\/span><\/code><\/pre>定义SSDT结构体<\/h4> typedef<\/span> struct<\/span> ServiceDescriptorEntry { <\/span><\/span> unsigned<\/span> int<\/span> *<\/span>ServiceTableBase; <\/span><\/span> unsigned<\/span> int<\/span> *<\/span>ServiceCounterTableBase; <\/span><\/span> unsigned<\/span> int<\/span> NumberOfServices; <\/span><\/span> unsigned<\/span> char<\/span> *<\/span>ParamTableBase; <\/span><\/span>} ServiceDescriptorTableEntry_t, *<\/span>PServiceDescriptorTableEntry_t; <\/span><\/span> <\/span><\/span>__declspec<\/span>(dllimport) ServiceDescriptorTableEntry_t KeServiceDescriptorTable; <\/span><\/span><\/code><\/pre>编写跳转代码<\/h4> void<\/span> _declspec<\/span>(naked<\/span>) NewNtOpenFile() { <\/span><\/span> __asm<\/span> { <\/span><\/span> pushad <\/span><\/span> pushfd <\/span><\/span> push p <\/span><\/span> call FilterNtOpenFile <\/span><\/span> popfd <\/span><\/span> popad <\/span><\/span> mov ebp, esp <\/span><\/span> xor eax, eax <\/span><\/span> push eax <\/span><\/span> jmp ReAddress <\/span><\/span> } <\/span><\/span>} <\/span><\/span><\/code><\/pre>3. 计算跳转地址<\/h3> 确定Hook位置（示例中选择偏移3处）<\/li> 计算返回地址（原始地址+偏移+5）<\/li> 计算跳转偏移量<\/li> <\/ol> UCHAR jmp_code[5<\/span>] =<\/span> ""<\/span>; <\/span><\/span>ULONG ChangeAddr =<\/span> 3<\/span>; <\/span><\/span>StartAddr =<\/span> KeServiceDescriptorTable.ServiceTableBase[116<\/span>]; <\/span><\/span>ReAddress =<\/span> StartAddr +<\/span> ChangeAddr +<\/span> 5<\/span>; <\/span><\/span>ULONG jmpAddr =<\/span> (ULONG)NewNtOpenFile -<\/span> StartAddr -<\/span> ChangeAddr -<\/span> 5<\/span>; <\/span><\/span> <\/span><\/span>jmp_code[0<\/span>] =<\/span> 0xE9<\/span>; <\/span><\/span>*<\/span>(ULONG*<\/span>)&<\/span>jmp_code[1<\/span>] =<\/span> jmpAddr; <\/span><\/span><\/code><\/pre>4. 修改内存保护<\/h3> 关闭页保护<\/h4> void<\/span> _declspec<\/span>(naked<\/span>) ShutPageProtect() { <\/span><\/span> __asm<\/span> { <\/span><\/span> push eax; <\/span><\/span> mov eax, cr0; <\/span><\/span> and eax, ~<\/span>0x10000<\/span>; <\/span><\/span> mov cr0, eax; <\/span><\/span> pop eax; <\/span><\/span> ret; <\/span><\/span> } <\/span><\/span>} <\/span><\/span><\/code><\/pre>执行Hook<\/h4> ShutPageProtect(); <\/span><\/span>RtlCopyMemory(Old_code, (PVOID)(StartAddr +<\/span> ChangeAddr), 5<\/span>); <\/span><\/span>RtlCopyMemory((PVOID)(StartAddr +<\/span> ChangeAddr), jmp_code, 5<\/span>); <\/span><\/span>OpenPageProtect(); <\/span><\/span><\/code><\/pre>恢复页保护<\/h4> void<\/span> _declspec<\/span>(naked<\/span>) OpenPageProtect() { <\/span><\/span> __asm<\/span> { <\/span><\/span> push eax; <\/span><\/span> mov eax, cr0; <\/span><\/span> or eax, 0x10000<\/span>; <\/span><\/span> mov cr0, eax; <\/span><\/span> pop eax; <\/span><\/span> ret; <\/span><\/span> } <\/span><\/span>} <\/span><\/span><\/code><\/pre>5. 卸载Hook<\/h3> void<\/span> UnHookNtOpenFile<\/span>() { <\/span><\/span> ULONG ChangeAddr =<\/span> 3<\/span>; <\/span><\/span> ShutPageProtect(); <\/span><\/span> RtlCopyMemory((PVOID)(StartAddr +<\/span> ChangeAddr), Old_code, 5<\/span>); <\/span><\/span> OpenPageProtect(); <\/span><\/span>} <\/span><\/span><\/code><\/pre>完整实现代码<\/h2> #include<\/span> <ntddk.h><\/span> <\/span><\/span><\/span><\/span> <\/span><\/span>typedef<\/span> struct<\/span> ServiceDescriptorEntry { <\/span><\/span> unsigned<\/span> int<\/span> *<\/span>ServiceTableBase; <\/span><\/span> unsigned<\/span> int<\/span> *<\/span>ServiceCounterTableBase; <\/span><\/span> unsigned<\/span> int<\/span> NumberOfServices; <\/span><\/span> unsigned<\/span> char<\/span> *<\/span>ParamTableBase; <\/span><\/span>} ServiceDescriptorTableEntry_t, *<\/span>PServiceDescriptorTableEntry_t; <\/span><\/span> <\/span><\/span>__declspec<\/span>(dllimport) ServiceDescriptorTableEntry_t KeServiceDescriptorTable; <\/span><\/span> <\/span><\/span>\/\/ 关闭页只读保护 <\/span><\/span><\/span><\/span>void<\/span> ShutPageProtect<\/span>(); <\/span><\/span>\/\/ 开启页只读保护 <\/span><\/span><\/span><\/span>void<\/span> OpenPageProtect<\/span>(); <\/span><\/span>\/\/ 测试函数 <\/span><\/span><\/span><\/span>void<\/span> FilterNtOpenFile<\/span>(char<\/span> *<\/span>p); <\/span><\/span>\/\/ 新NtOpenFile <\/span><\/span><\/span><\/span>void<\/span> NewNtOpenFile<\/span>(); <\/span><\/span>\/\/ hook NtOpenFile <\/span><\/span><\/span><\/span>void<\/span> HookNtOpenFile<\/span>(); <\/span><\/span>\/\/ unhook NtOpenFile <\/span><\/span><\/span><\/span>void<\/span> UnHookNtOpenFile<\/span>(); <\/span><\/span> <\/span><\/span>\/\/关闭页只读保护 <\/span><\/span><\/span><\/span>void<\/span> _declspec<\/span>(naked<\/span>) ShutPageProtect() { <\/span><\/span> __asm<\/span> { <\/span><\/span> push eax; <\/span><\/span> mov eax, cr0; <\/span><\/span> and eax, ~<\/span>0x10000<\/span>; <\/span><\/span> mov cr0, eax; <\/span><\/span> pop eax; <\/span><\/span> ret; <\/span><\/span> } <\/span><\/span>} <\/span><\/span> <\/span><\/span>\/\/开启页只读保护 <\/span><\/span><\/span><\/span>void<\/span> _declspec<\/span>(naked<\/span>) OpenPageProtect() { <\/span><\/span> __asm<\/span> { <\/span><\/span> push eax; <\/span><\/span> mov eax, cr0; <\/span><\/span> or eax, 0x10000<\/span>; <\/span><\/span> mov cr0, eax; <\/span><\/span> pop eax; <\/span><\/span> ret; <\/span><\/span> } <\/span><\/span>} <\/span><\/span> <\/span><\/span>ULONG StartAddr; <\/span><\/span>ULONG ReAddress; <\/span><\/span>UCHAR Old_code[5<\/span>]; <\/span><\/span>char<\/span> *<\/span>p =<\/span> "r0 InlineHook"<\/span>; <\/span><\/span> <\/span><\/span>void<\/span> FilterNtOpenFile<\/span>(char<\/span> *<\/span>p) { <\/span><\/span> KdPrint(("%s <\/span>\r\n<\/span>"<\/span>, p)); <\/span><\/span> KdPrint(("name:%s <\/span>\r\n<\/span>"<\/span>, (char<\/span>*<\/span>)PsGetCurrentProcess() +<\/span> 0x174<\/span>)); <\/span><\/span>} <\/span><\/span> <\/span><\/span>void<\/span> _declspec<\/span>(naked<\/span>) NewNtOpenFile() { <\/span><\/span> __asm<\/span> { <\/span><\/span> pushad <\/span><\/span> pushfd <\/span><\/span> push p <\/span><\/span> call FilterNtOpenFile <\/span><\/span> popfd <\/span><\/span> popad <\/span><\/span> mov ebp, esp <\/span><\/span> xor eax, eax <\/span><\/span> push eax <\/span><\/span> jmp ReAddress <\/span><\/span> } <\/span><\/span>} <\/span><\/span> <\/span><\/span>void<\/span> HookNtOpenFile<\/span>() { <\/span><\/span> \/\/ 存放跳转指令的数组 <\/span><\/span><\/span><\/span> UCHAR jmp_code[5<\/span>] =<\/span> ""<\/span>; <\/span><\/span> \/\/ 在入口0x3处hook <\/span><\/span><\/span><\/span> ULONG ChangeAddr =<\/span> 3<\/span>; <\/span><\/span> \/\/ NtOpenFile函数的开始地址 <\/span><\/span><\/span><\/span> StartAddr =<\/span> KeServiceDescriptorTable.ServiceTableBase[116<\/span>]; <\/span><\/span> \/\/ 返回地址 <\/span><\/span><\/span><\/span> ReAddress =<\/span> StartAddr +<\/span> ChangeAddr +<\/span> 5<\/span>; <\/span><\/span> \/\/ newNtOpenKey相对于NtOpenKey的偏移量 <\/span><\/span><\/span><\/span> ULONG jmpAddr =<\/span> (ULONG)NewNtOpenFile -<\/span> StartAddr -<\/span> ChangeAddr -<\/span> 5<\/span>; <\/span><\/span> \/\/ 使用jmp指令跳转,jmp = 0xE9 <\/span><\/span><\/span><\/span> jmp_code[0<\/span>] =<\/span> 0xE9<\/span>; <\/span><\/span> \/\/ 填入偏移地址 <\/span><\/span><\/span><\/span> *<\/span>(ULONG*<\/span>)&<\/span>jmp_code[1<\/span>] =<\/span> jmpAddr; <\/span><\/span> <\/span><\/span> ShutPageProtect(); <\/span><\/span> RtlCopyMemory(Old_code, (PVOID)(StartAddr +<\/span> ChangeAddr), 5<\/span>); <\/span><\/span> RtlCopyMemory((PVOID)(StartAddr +<\/span> ChangeAddr), jmp_code, 5<\/span>); <\/span><\/span> OpenPageProtect(); <\/span><\/span>} <\/span><\/span> <\/span><\/span>void<\/span> UnHookNtOpenFile<\/span>() { <\/span><\/span> ULONG ChangeAddr =<\/span> 3<\/span>; <\/span><\/span> ShutPageProtect(); <\/span><\/span> RtlCopyMemory((PVOID)(StartAddr +<\/span> ChangeAddr), Old_code, 5<\/span>); <\/span><\/span> OpenPageProtect(); <\/span><\/span>} <\/span><\/span> <\/span><\/span>\/\/卸载驱动 <\/span><\/span><\/span><\/span>void<\/span> DriverUnload<\/span>(DRIVER_OBJECT *<\/span>obj) { <\/span><\/span> \/\/卸载钩子 <\/span><\/span><\/span><\/span> UnHookNtOpenFile(); <\/span><\/span> KdPrint(("驱动卸载成功! <\/span>\n<\/span>"<\/span>)); <\/span><\/span>} <\/span><\/span> <\/span><\/span>\/***驱动入口主函数***\/<\/span> <\/span><\/span>NTSTATUS DriverEntry<\/span>(DRIVER_OBJECT *<\/span>driver, UNICODE_STRING *<\/span>path) { <\/span><\/span> KdPrint(("驱动启动成功! <\/span>\n<\/span>"<\/span>)); <\/span><\/span> \/\/安装钩子 <\/span><\/span><\/span><\/span> HookNtOpenFile(); <\/span><\/span> driver-><\/span>DriverUnload =<\/span> DriverUnload; <\/span><\/span> return<\/span> STATUS_SUCCESS; <\/span><\/span>} <\/span><\/span><\/code><\/pre>关键注意事项<\/h2> 指令选择<\/strong>：选择修改的指令不能是涉及全局变量或重定位地址的指令<\/li> 内存保护<\/strong>：修改内核代码前必须关闭CR0的WP位（写保护）<\/li> 寄存器保存<\/strong>：在跳转代码中要保存和恢复所有寄存器状态<\/li> 原始指令保存<\/strong>：必须保存被覆盖的原始指令以便正确恢复<\/li> 偏移计算<\/strong>：跳转偏移量计算要准确，确保能正确跳转和返回<\/li> <\/ol> 总结<\/h2> Ring0下的Inline Hook技术通过直接修改内核函数代码实现挂钩，具有较高的隐蔽性。实现过程中需要注意内存保护机制、指令选择和偏移计算等关键点。这种技术可用于内核监控、安全防护等多种场景，但使用时需遵守相关法律法规。<\/p>