腾讯游戏安全大赛2024决赛题解
作者论坛账号：xia0ji233
决赛打五天，是真的顶级，但是五天比一年学的东西都多...
本题解题附件自取
2024腾讯游戏安全竞赛决赛题解
分析
自行加载loader.sys, 找到用户名为administrator的KEY，作为答案提交（1分）
Key 和 User 默认读 C:\card.txt，如果找不到或者是错误，那么加载会失败，于是想到 hook NtCreateFile 获取到文件句柄，再 hook NtReadFile 找到文件内容写入的地址。
复制代码 隐藏代码#include <ntifs.h> #include <ntdef.h> #include <ntstatus.h> #include <ntddk.h> #define MAX_BACKTRACE_DEPTH 20 #define SYMBOL L"\\??\\xia0ji2333" #define kprintf(format, ...) DbgPrintEx(DPFLTR_IHVDRIVER_ID, DPFLTR_ERROR_LEVEL, format, ##__VA_ARGS__) UINT64 BaseAddr=NULL, DLLSize=0; void DeleteDevice(PDRIVER_OBJECT pDriver) { kprintf(("Line %d:xia0ji233: start delete device\n"), __LINE__); if (pDriver->DeviceObject) { UNICODE_STRING Sym; RtlInitUnicodeString(&Sym, SYMBOL);//CreateFile kprintf(("Line %d:xia0ji233: Delete Symbol\n"), __LINE__); IoDeleteSymbolicLink(&Sym); kprintf(("Line %d:xia0ji233: Delete Device\n"), __LINE__); IoDeleteDevice(pDriver->DeviceObject); } kprintf(("Line %d:xia0ji233: end delete device\n"), __LINE__); } HANDLE FileHandler = NULL; char newcode[] = { 0x48,0xB8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//mov rax,xxx 0xFF,0xE0//jmp rax }; char oldcode[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00, }; char newcode2[] = { 0x48,0xB8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//mov rax,xxx 0xFF,0xE0//jmp rax }; char oldcode2[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00, }; char* target; char* target2; KIRQL WPOFFx64() { KIRQL irql = KeRaiseIrqlToDpcLevel(); UINT64 cr0 = __readcr0(); cr0 &= 0xfffffffffffeffff; __writecr0(cr0); _disable(); return irql; } void WPONx64(KIRQL irql) { UINT64 cr0 = __readcr0(); cr0 |= 0x10000; _enable(); __writecr0(cr0); KeLowerIrql(irql); } NTSTATUS Unhook() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode); i++) { target[i] = oldcode[i]; } WPONx64(irql); return STATUS_SUCCESS; } NTSTATUS Unhook2() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode2); i++) { target2[i] = oldcode2[i]; } WPONx64(irql); return STATUS_SUCCESS; } NTSTATUS Hook() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode); i++) { target[i] = newcode[i]; } WPONx64(irql); return STATUS_SUCCESS; } NTSTATUS Hook2() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode2); i++) { target2[i] = newcode2[i]; } WPONx64(irql); return STATUS_SUCCESS; } PDRIVER_OBJECT g_Object = NULL; typedef struct _LDR_DATA_TABLE_ENTRY { LIST_ENTRY InLoadOrderLinks; LIST_ENTRY InMemoryOrderLinks; LIST_ENTRY InInitializationOrderLinks; PVOID DllBase; PVOID EntryPoint;//驱动的进入点 DriverEntry ULONG SizeOfImage; UNICODE_STRING FullDllName;//驱动的满路径 UNICODE_STRING BaseDllName;//不带路径的驱动名字 ULONG Flags; USHORT LoadCount; USHORT TlsIndex; union { LIST_ENTRY HashLinks; struct { PVOID SectionPointer; ULONG CheckSum; }; }; union { struct { ULONG TimeDateStamp; }; struct { PVOID LoadedImports; }; }; } LDR_DATA_TABLE_ENTRY, *PLDR_DATA_TABLE_ENTRY; typedef NTSTATUS (* FuncPtr) ( _Out_ PHANDLE FileHandle, _In_ ACCESS_MASK DesiredAccess, _In_ POBJECT_ATTRIBUTES ObjectAttributes, _Out_ PIO_STATUS_BLOCK IoStatusBlock, _In_opt_ PLARGE_INTEGER AllocationSize, _In_ ULONG FileAttributes, _In_ ULONG ShareAccess, _In_ ULONG CreateDisposition, _In_ ULONG CreateOptions, _In_reads_bytes_opt_(EaLength) PVOID EaBuffer, _In_ ULONG EaLength ); typedef NTSTATUS (* FuncPtr2 )( _In_ HANDLE FileHandle, _In_opt_ HANDLE Event, _In_opt_ PIO_APC_ROUTINE ApcRoutine, _In_opt_ PVOID ApcContext, _Out_ PIO_STATUS_BLOCK IoStatusBlock, _Out_writes_bytes_(Length) PVOID Buffer, _In_ ULONG Length, _In_opt_ PLARGE_INTEGER ByteOffset, _In_opt_ PULONG Key ); ULONG myCreateFile(_Out_ PHANDLE FileHandle, _In_ ACCESS_MASK DesiredAccess, _In_ POBJECT_ATTRIBUTES ObjectAttributes, _Out_ PIO_STATUS_BLOCK IoStatusBlock, _In_opt_ PLARGE_INTEGER AllocationSize, _In_ ULONG FileAttributes, _In_ ULONG ShareAccess, _In_ ULONG CreateDisposition, _In_ ULONG CreateOptions, _In_reads_bytes_opt_(EaLength) PVOID EaBuffer, _In_ ULONG EaLength) { Unhook(); FuncPtr func = (FuncPtr)target; NTSTATUS s = func(FileHandle,DesiredAccess,ObjectAttributes,IoStatusBlock,AllocationSize,FileAttributes,ShareAccess,CreateDisposition,CreateOptions,EaBuffer,EaLength); if (!wcscmp(ObjectAttributes->ObjectName->Buffer, L"\\??\\C:\\card.txt")) { kprintf(("call NtCreateFile(%p,%p,%S,%p,%p,%p,%p,%p,%p,%p,%p)\n"), FileHandle,DesiredAccess,ObjectAttributes->ObjectName->Buffer,IoStatusBlock,AllocationSize,FileAttributes,ShareAccess,CreateDisposition,CreateOptions,EaBuffer,EaLength); DbgBreakPoint(); FileHandler = *FileHandle; } //DbgBreakPoint(); Hook(); return s; } ULONG myReadFile( _In_ HANDLE FileHandle, _In_opt_ HANDLE Event, _In_opt_ PIO_APC_ROUTINE ApcRoutine, _In_opt_ PVOID ApcContext, _Out_ PIO_STATUS_BLOCK IoStatusBlock, _Out_writes_bytes_(Length) PVOID Buffer, _In_ ULONG Length, _In_opt_ PLARGE_INTEGER ByteOffset, _In_opt_ PULONG Key) { Unhook2(); FuncPtr2 func = (FuncPtr2)target2; if (FileHandler && FileHandler == FileHandle) { kprintf(("call NtReadFile(%p,%p,%p,%p,%p,%p,%p,%p,%p)\n"), FileHandle, Event, ApcRoutine, ApcContext, IoStatusBlock, Buffer, Length, ByteOffset, Key); DbgBreakPoint(); FileHandler = 0; } //DbgBreakPoint(); NTSTATUS s = func(FileHandle,Event,ApcRoutine,ApcContext,IoStatusBlock,Buffer,Length,ByteOffset,Key); Hook2(); return s; } void DriverUnload(PDRIVER_OBJECT pDriver) { kprintf(("Line %d:xia0ji233: start unload\n"), __LINE__); Unhook(); Unhook2(); DeleteDevice(pDriver); } NTSTATUS DriverEntry( _In_ PDRIVER_OBJECT DriverObject, _In_ PUNICODE_STRING RegistryPath ) { DriverObject->DriverUnload = DriverUnload; kprintf(("Line %d:xia0ji233: RegistryPath = %S\n"), __LINE__, RegistryPath->Buffer); target = NtCreateFile; target2 = NtReadFile; kprintf(("Line %d:xia0ji233: NtCreateFile=%p NtReadFile=%p\n"), __LINE__, target,target2); g_Object = DriverObject; if (target&&target2) { for (int i = 0; i < sizeof(oldcode); i++) { oldcode[i] = target[i]; oldcode2[i] = target2[i]; } *(UINT64*)(newcode + 2) = myCreateFile; *(UINT64*)(newcode2 + 2) = myReadFile; Hook(); Hook2(); } else { kprintf(("xia0ji233:hahaha")); } return 0; }
跟到后面可以找到文件内容（ReadFile第六个参数），在文件内容处下硬件读取断点，可以找到这里文件内容被被写入两个寄存器，随后又写入另外的内存（RCX所指向的内存）。
然后就直接 ret 了，这里将内存窗口转到 RCX 指向的地址，然后程序跳出来。
紧接着给末尾添 0 字节，然后将 r14 与 0x10 比较，小于跳出
这一次输出失败了，于是考虑换长度但是改一个字符，发现在另外的位置写了零字节
在跟的过程中，发现后面的一个内存就是长度
然后接着跟，会跟到一个找 - 的代码
很容易理解，因为 - 就是分隔 user 和 key 的，必然有一个遍历在找 - 的位置，那就直接跳到它找到了 - 的位置，发现有一个大跳转
随后会把 - 所处的地址存入栈中
紧接着跟，发现把User拷贝到下面的内存了
随后将key也写入下方的内存
然后开始循环 key，判断如果 -0x30 是否 >10，应该 key 只能是数字的判断。
于是我在循环这里下了一个软件断点，发现 RDI 会存储当前已遍历的十进制。
例如现在已经遍历到了 405，那么 rdi=0x195=405。
经过数次的循环，
可以发现 RDI=0xF17E203C，就是 4051574844，那么接下来就往下面跟看看跟 User 有什么样的关系。
取出ACE之后算出一个值 0x0000000020450083，最后很 0x1003F 相乘，得到 00000000F17E203D，刚好是题目所给 key 的十六进制表示。
后面通过一定的调试分析，发现一个规律
似乎它会把每一个字符加起来然后 *0x1003F，并且一定是 int。
先验证一遍ACE是否正确
发现果然如此，那么照样子算出 key 为 4007951923。
编写一个keygen，能生成对于任何用户名的KEY（1分）
根据上面的分析，不难写出 keygen 程序
复制代码 隐藏代码#include<stdio.h> #include<string.h> int main(){ char user[]="xia0ji233"; int n=strlen(user); unsigned key=0; for(int i=0;i<n;i++){ key=(key+user[i])*0x1003F; } printf("%u\n",key); }
运行即可获得 key 的输出。
编写一个exp，在exp程序运行后，对于任意的用户名-key，Loader.sys均能正确启动（1分）
有这么几种方法：监控内核线程，在 shellcode 执行的时候拦截，把比较是否相等的代码patch掉。监控文件读写，在读文件的时候，判断如果是目标文件，让它返回正确的结果。
最后还是选择在文件处拦截，然后趁它读文件的时候遍历驱动模块改它代码，上面分析的 imul 关键指令在 Loader.sys+0xafc1c4 的位置
再调试一遍，决出关键一步，找到了 cmp 指令
如图所示的内存分别为实际输入的数值和通过 user 计算得到的key的数值，随后取出相比较，不相等显然跳转到 Fail 分支，因此这里改成 NOP 让它不跳转任意情况下跳转成功。
此时的 sys 基地址为 0xFFFFF806F82D0000，与该指令相减得到 0xa27e 的偏移，只需把这两个字节改成 0x90 即可达到任意的 user key 可以成功加载驱动。
我先使用了hook的方式去劫持，确保劫持的函数没错，再通过修改劫持时机和方式让方法满足要求
复制代码 隐藏代码#include <ntifs.h> #include <ntdef.h> #include <ntstatus.h> #include <ntddk.h> #define MAX_BACKTRACE_DEPTH 20 #define SYMBOL L"\\??\\xia0ji2333" #define kprintf(format, ...) DbgPrintEx(DPFLTR_IHVDRIVER_ID, DPFLTR_ERROR_LEVEL, format, ##__VA_ARGS__) UINT64 BaseAddr=NULL, DLLSize=0; void DeleteDevice(PDRIVER_OBJECT pDriver) { kprintf(("Line %d:xia0ji233: start delete device\n"), __LINE__); if (pDriver->DeviceObject) { UNICODE_STRING Sym; RtlInitUnicodeString(&Sym, SYMBOL);//CreateFile kprintf(("Line %d:xia0ji233: Delete Symbol\n"), __LINE__); IoDeleteSymbolicLink(&Sym); kprintf(("Line %d:xia0ji233: Delete Device\n"), __LINE__); IoDeleteDevice(pDriver->DeviceObject); } kprintf(("Line %d:xia0ji233: end delete device\n"), __LINE__); } HANDLE FileHandler = NULL; char newcode[] = { 0x48,0xB8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//mov rax,xxx 0xFF,0xE0//jmp rax }; char oldcode[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00, }; char newcode2[] = { 0x48,0xB8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//mov rax,xxx 0xFF,0xE0//jmp rax }; char oldcode2[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00, }; char* target; char* target2; KIRQL WPOFFx64() { KIRQL irql = KeRaiseIrqlToDpcLevel(); UINT64 cr0 = __readcr0(); cr0 &= 0xfffffffffffeffff; __writecr0(cr0); _disable(); return irql; } void WPONx64(KIRQL irql) { UINT64 cr0 = __readcr0(); cr0 |= 0x10000; _enable(); __writecr0(cr0); KeLowerIrql(irql); } NTSTATUS Unhook() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode); i++) { target[i] = oldcode[i]; } WPONx64(irql); return STATUS_SUCCESS; } NTSTATUS Unhook2() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode2); i++) { target2[i] = oldcode2[i]; } WPONx64(irql); return STATUS_SUCCESS; } NTSTATUS Hook() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode); i++) { target[i] = newcode[i]; } WPONx64(irql); return STATUS_SUCCESS; } NTSTATUS Hook2() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode2); i++) { target2[i] = newcode2[i]; } WPONx64(irql); return STATUS_SUCCESS; } PDRIVER_OBJECT g_Object = NULL; typedef struct _LDR_DATA_TABLE_ENTRY { LIST_ENTRY InLoadOrderLinks; LIST_ENTRY InMemoryOrderLinks; LIST_ENTRY InInitializationOrderLinks; PVOID DllBase; PVOID EntryPoint;//驱动的进入点 DriverEntry ULONG SizeOfImage; UNICODE_STRING FullDllName;//驱动的满路径 UNICODE_STRING BaseDllName;//不带路径的驱动名字 ULONG Flags; USHORT LoadCount; USHORT TlsIndex; union { LIST_ENTRY HashLinks; struct { PVOID SectionPointer; ULONG CheckSum; }; }; union { struct { ULONG TimeDateStamp; }; struct { PVOID LoadedImports; }; }; } LDR_DATA_TABLE_ENTRY, *PLDR_DATA_TABLE_ENTRY; typedef NTSTATUS (* FuncPtr) ( _Out_ PHANDLE FileHandle, _In_ ACCESS_MASK DesiredAccess, _In_ POBJECT_ATTRIBUTES ObjectAttributes, _Out_ PIO_STATUS_BLOCK IoStatusBlock, _In_opt_ PLARGE_INTEGER AllocationSize, _In_ ULONG FileAttributes, _In_ ULONG ShareAccess, _In_ ULONG CreateDisposition, _In_ ULONG CreateOptions, _In_reads_bytes_opt_(EaLength) PVOID EaBuffer, _In_ ULONG EaLength ); typedef NTSTATUS (* FuncPtr2 )( _In_ HANDLE FileHandle, _In_opt_ HANDLE Event, _In_opt_ PIO_APC_ROUTINE ApcRoutine, _In_opt_ PVOID ApcContext, _Out_ PIO_STATUS_BLOCK IoStatusBlock, _Out_writes_bytes_(Length) PVOID Buffer, _In_ ULONG Length, _In_opt_ PLARGE_INTEGER ByteOffset, _In_opt_ PULONG Key ); NTSTATUS EnumerateKernelThreads(); typedef NTSTATUS (*ZWQUERYSYSTEMINFORMATION)(ULONG, PVOID, ULONG, PULONG); typedef struct _SYSTEM_PROCESS_INFORMATION { ULONG NextEntryOffset; ULONG NumberOfThreads; LARGE_INTEGER Reserved[3]; LARGE_INTEGER CreateTime; LARGE_INTEGER UserTime; LARGE_INTEGER KernelTime; UNICODE_STRING ImageName; ULONG BasePriority; HANDLE ProcessId; HANDLE InheritedFromProcessId; } SYSTEM_PROCESS_INFORMATION, *PSYSTEM_PROCESS_INFORMATION; typedef struct _SYSTEM_THREAD_INFORMATION { LARGE_INTEGER KernelTime; LARGE_INTEGER UserTime; LARGE_INTEGER CreateTime; ULONG WaitTime; PVOID StartAddress; CLIENT_ID ClientId; ULONG Priority; LONG BasePriority; ULONG ContextSwitchCount; LONG State; LONG WaitReason; } SYSTEM_THREAD_INFORMATION, *PSYSTEM_THREAD_INFORMATION; typedef enum _SYSTEM_INFORMATION_CLASS { SystemProcessInformation = 5 } SYSTEM_INFORMATION_CLASS; #define SystemModuleInformation 11 ULONG myCreateFile(_Out_ PHANDLE FileHandle, _In_ ACCESS_MASK DesiredAccess, _In_ POBJECT_ATTRIBUTES ObjectAttributes, _Out_ PIO_STATUS_BLOCK IoStatusBlock, _In_opt_ PLARGE_INTEGER AllocationSize, _In_ ULONG FileAttributes, _In_ ULONG ShareAccess, _In_ ULONG CreateDisposition, _In_ ULONG CreateOptions, _In_reads_bytes_opt_(EaLength) PVOID EaBuffer, _In_ ULONG EaLength) { Unhook(); FuncPtr func = (FuncPtr)target; NTSTATUS s = func(FileHandle,DesiredAccess,ObjectAttributes,IoStatusBlock,AllocationSize,FileAttributes,ShareAccess,CreateDisposition,CreateOptions,EaBuffer,EaLength); if (!wcscmp(ObjectAttributes->ObjectName->Buffer, L"\\??\\C:\\card.txt")) { kprintf(("call NtCreateFile(%p,%p,%S,%p,%p,%p,%p,%p,%p,%p,%p)\n"), FileHandle,DesiredAccess,ObjectAttributes->ObjectName->Buffer,IoStatusBlock,AllocationSize,FileAttributes,ShareAccess,CreateDisposition,CreateOptions,EaBuffer,EaLength); //DbgBreakPoint(); FileHandler = *FileHandle; } //DbgBreakPoint(); Hook(); return s; } MDLWriteMemory(PVOID pBaseAddress, PVOID pWriteData, SIZE_T writeDataSize) { PMDL pMdl = NULL; PVOID pNewAddress = NULL; pMdl = MmCreateMdl(NULL, pBaseAddress, writeDataSize); if (NULL == pMdl) { return FALSE; } MmBuildMdlForNonPagedPool(pMdl); pNewAddress = MmMapLockedPages(pMdl, KernelMode); if (NULL == pNewAddress) { IoFreeMdl(pMdl); } RtlCopyMemory(pNewAddress, pWriteData, writeDataSize); MmUnmapLockedPages(pNewAddress, pMdl); IoFreeMdl(pMdl); return TRUE; } VOID PatchInstr() { LDR_DATA_TABLE_ENTRY *TE, *Tmp; TE = (LDR_DATA_TABLE_ENTRY*)g_Object->DriverSection; PLIST_ENTRY LinkList; ; int i = 0; LinkList = TE->InLoadOrderLinks.Flink; UNICODE_STRING name; RtlInitUnicodeString(&name,L"Loader.sys"); ; while (LinkList != &TE->InLoadOrderLinks) { Tmp = (LDR_DATA_TABLE_ENTRY*)LinkList; if (RtlEqualUnicodeString(&Tmp->BaseDllName, &name,FALSE)) { kprintf(("DLLname:%S DLLBase=%p nowcode=%p\n"), Tmp->BaseDllName.Buffer,Tmp->DllBase,(ULONG64)(Tmp->DllBase) + 0xa27e); char buffer[] = { 0x90,0x90 }; MDLWriteMemory((ULONG64)(Tmp->DllBase) + 0xa27e, buffer, 2); return; } LinkList = LinkList->Flink; i++; } } ULONG myReadFile( _In_ HANDLE FileHandle, _In_opt_ HANDLE Event, _In_opt_ PIO_APC_ROUTINE ApcRoutine, _In_opt_ PVOID ApcContext, _Out_ PIO_STATUS_BLOCK IoStatusBlock, _Out_writes_bytes_(Length) PVOID Buffer, _In_ ULONG Length, _In_opt_ PLARGE_INTEGER ByteOffset, _In_opt_ PULONG Key) { Unhook2(); FuncPtr2 func = (FuncPtr2)target2; if (FileHandler && FileHandler == FileHandle) { kprintf(("call NtReadFile(%p,%p,%p,%p,%p,%p,%p,%p,%p)\n"), FileHandle, Event, ApcRoutine, ApcContext, IoStatusBlock, Buffer, Length, ByteOffset, Key); kprintf(("buffer in %p\n"), Buffer); PatchInstr(); FileHandler = 0; } //DbgBreakPoint(); NTSTATUS s = func(FileHandle,Event,ApcRoutine,ApcContext,IoStatusBlock,Buffer,Length,ByteOffset,Key); Hook2(); return s; } void DriverUnload(PDRIVER_OBJECT pDriver) { kprintf(("Line %d:xia0ji233: start unload\n"), __LINE__); Unhook(); Unhook2(); DeleteDevice(pDriver); } NTSTATUS DriverEntry( _In_ PDRIVER_OBJECT DriverObject, _In_ PUNICODE_STRING RegistryPath ) { DriverObject->DriverUnload = DriverUnload; kprintf(("Line %d:xia0ji233: RegistryPath = %S\n"), __LINE__, RegistryPath->Buffer); target = NtCreateFile; target2 = NtReadFile; kprintf(("Line %d:xia0ji233: NtCreateFile=%p NtReadFile=%p\n"), __LINE__, target,target2); g_Object = DriverObject; if (target&&target2) { for (int i = 0; i < sizeof(oldcode); i++) { oldcode[i] = target[i]; oldcode2[i] = target2[i]; } *(UINT64*)(newcode + 2) = myCreateFile; *(UINT64*)(newcode2 + 2) = myReadFile; Hook(); Hook2(); } else { kprintf(("xia0ji233:hahaha")); } return 0; } int Filter(ULONG Start) { LDR_DATA_TABLE_ENTRY *TE, *Tmp; TE = (LDR_DATA_TABLE_ENTRY*)g_Object->DriverSection; PLIST_ENTRY LinkList; ; int i = 0; LinkList = TE->InLoadOrderLinks.Flink; while (LinkList != &TE->InLoadOrderLinks) { Tmp = (LDR_DATA_TABLE_ENTRY*)LinkList; ULONG BASE = Tmp->DllBase; ULONG Size = Tmp->SizeOfImage; if (Start >= BASE && Start < BASE + Size) { return 0; } LinkList = LinkList->Flink; i++; } return 1; }
可以看到，先加载我写的驱动，后加载题目驱动，无论 user-key 正确与否，都加载成功
于是这里把修改的函数套到文件读取里面去拦截，达到读该文件时遍历模块，找到指定模块则写入指令。
下面是真正的代码（编译文件为XSafe2.sys）
复制代码 隐藏代码#include <ntifs.h> #include <ntdef.h> #include <ntstatus.h> #include <ntddk.h> #define kprintf(format, ...) DbgPrintEx(DPFLTR_IHVDRIVER_ID, DPFLTR_ERROR_LEVEL, format, ##__VA_ARGS__) 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; }; }; 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; NTSTATUS DriverEntry(PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegistryPath); VOID UnloadDriver(PDRIVER_OBJECT DriverObject); NTSTATUS EnumerateKernelThreads(); typedef NTSTATUS (*ZWQUERYSYSTEMINFORMATION)(ULONG, PVOID, ULONG, PULONG); typedef struct _SYSTEM_PROCESS_INFORMATION { ULONG NextEntryOffset; ULONG NumberOfThreads; LARGE_INTEGER Reserved[3]; LARGE_INTEGER CreateTime; LARGE_INTEGER UserTime; LARGE_INTEGER KernelTime; UNICODE_STRING ImageName; ULONG BasePriority; HANDLE ProcessId; HANDLE InheritedFromProcessId; } SYSTEM_PROCESS_INFORMATION, *PSYSTEM_PROCESS_INFORMATION; typedef struct _SYSTEM_THREAD_INFORMATION { LARGE_INTEGER KernelTime; LARGE_INTEGER UserTime; LARGE_INTEGER CreateTime; ULONG WaitTime; PVOID StartAddress; CLIENT_ID ClientId; ULONG Priority; LONG BasePriority; ULONG ContextSwitchCount; LONG State; LONG WaitReason; } SYSTEM_THREAD_INFORMATION, *PSYSTEM_THREAD_INFORMATION; typedef enum _SYSTEM_INFORMATION_CLASS { SystemProcessInformation = 5 } SYSTEM_INFORMATION_CLASS; #define SystemModuleInformation 11 PVOID obHandle; DRIVER_INITIALIZE DriverEntry; PDRIVER_OBJECT g_Object = NULL; typedef struct _LDR_DATA_TABLE_ENTRY { LIST_ENTRY InLoadOrderLinks; LIST_ENTRY InMemoryOrderLinks; LIST_ENTRY InInitializationOrderLinks; PVOID DllBase; PVOID EntryPoint;//驱动的进入点 DriverEntry ULONG SizeOfImage; UNICODE_STRING FullDllName;//驱动的满路径 UNICODE_STRING BaseDllName;//不带路径的驱动名字 ULONG Flags; USHORT LoadCount; USHORT TlsIndex; union { LIST_ENTRY HashLinks; struct { PVOID SectionPointer; ULONG CheckSum; }; }; union { struct { ULONG TimeDateStamp; }; struct { PVOID LoadedImports; }; }; } LDR_DATA_TABLE_ENTRY, *PLDR_DATA_TABLE_ENTRY; MDLWriteMemory(PVOID pBaseAddress, PVOID pWriteData, SIZE_T writeDataSize) { PMDL pMdl = NULL; PVOID pNewAddress = NULL; pMdl = MmCreateMdl(NULL, pBaseAddress, writeDataSize); if (NULL == pMdl) { return FALSE; } MmBuildMdlForNonPagedPool(pMdl); pNewAddress = MmMapLockedPages(pMdl, KernelMode); if (NULL == pNewAddress) { IoFreeMdl(pMdl); } RtlCopyMemory(pNewAddress, pWriteData, writeDataSize); MmUnmapLockedPages(pNewAddress, pMdl); IoFreeMdl(pMdl); return TRUE; } VOID PatchInstr() { LDR_DATA_TABLE_ENTRY *TE, *Tmp; TE = (LDR_DATA_TABLE_ENTRY*)g_Object->DriverSection; PLIST_ENTRY LinkList; ; int i = 0; LinkList = TE->InLoadOrderLinks.Flink; UNICODE_STRING name; RtlInitUnicodeString(&name,L"Loader.sys"); ; while (LinkList != &TE->InLoadOrderLinks) { Tmp = (LDR_DATA_TABLE_ENTRY*)LinkList; if (RtlEqualUnicodeString(&Tmp->BaseDllName, &name,FALSE)) { kprintf(("DLLname:%S DLLBase=%p nowcode=%p\n"), Tmp->BaseDllName.Buffer,Tmp->DllBase,(ULONG64)(Tmp->DllBase) + 0xa27e); char buffer[] = { 0x90,0x90 }; MDLWriteMemory((ULONG64)(Tmp->DllBase) + 0xa27e, buffer, 2); return; } LinkList = LinkList->Flink; i++; } } // 文件回调 OB_PREOP_CALLBACK_STATUS FileObjectpreCall(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); if (!wcscmp(fileo->FileName.Buffer, L"\\card.txt")) { PETHREAD pct=PsGetCurrentThread(); PVOID addr=*(ULONG64*)((char*)pct + 0x450); PatchInstr(); //EnumerateKernelThreads(); DbgBreakPoint(); } 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; kprintf(("hello xia0ji233\n")); g_Object = Driver; 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)&FileObjectpreCall; status = ObRegisterCallbacks(&obRegFileCallBack, &obHandle); if (!NT_SUCCESS(status)) { kprintf(("注册回调错误 \n")); status = STATUS_UNSUCCESSFUL; } UNREFERENCED_PARAMETER(RegistryPath); Driver->DriverUnload = &UnDriver; return status; }
该程序（附件中的XSafe2.sys）先加载，再加载Loader.sys同样可以任意user key加载成功并且不hook任何系统API和文件。
分析shellcode反复在读取哪个内存地址（2分）
shellcode加载之后，会检测双机调试
但是有一定的延迟，说明是主动检测的不是被动触发的，刚好遇上这个题，猜测是检测了一个调试器标志位。
不过这里感觉是得先确定一下 shellcode 的位置的，因为它带反调，不知道它怎么反调的，突然想到之前一位神仙把蓝屏代码删了导致电脑爆炸，于是我也想效仿一下看看可不可彳亍。
复制代码 隐藏代码#include <ntifs.h> #include <ntdef.h> #include <ntstatus.h> #include <ntddk.h> #define MAX_BACKTRACE_DEPTH 20 #define SYMBOL L"\\??\\xia0ji2333" #define kprintf(format, ...) DbgPrintEx(DPFLTR_IHVDRIVER_ID, DPFLTR_ERROR_LEVEL, format, ##__VA_ARGS__) UINT64 BaseAddr=NULL, DLLSize=0; #define MAX_BACKTRACE_DEPTH 20 void DeleteDevice(PDRIVER_OBJECT pDriver) { kprintf(("Line %d:xia0ji233: start delete device\n"), __LINE__); if (pDriver->DeviceObject) { UNICODE_STRING Sym; RtlInitUnicodeString(&Sym, SYMBOL);//CreateFile kprintf(("Line %d:xia0ji233: Delete Symbol\n"), __LINE__); IoDeleteSymbolicLink(&Sym); kprintf(("Line %d:xia0ji233: Delete Device\n"), __LINE__); IoDeleteDevice(pDriver->DeviceObject); } kprintf(("Line %d:xia0ji233: end delete device\n"), __LINE__); } HANDLE FileHandler = NULL; char newcode[] = { 0x48,0xB8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//mov rax,xxx 0xFF,0xE0//jmp rax }; char oldcode[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00, }; char* target; KIRQL WPOFFx64() { KIRQL irql = KeRaiseIrqlToDpcLevel(); UINT64 cr0 = __readcr0(); cr0 &= 0xfffffffffffeffff; __writecr0(cr0); _disable(); return irql; } void WPONx64(KIRQL irql) { UINT64 cr0 = __readcr0(); cr0 |= 0x10000; _enable(); __writecr0(cr0); KeLowerIrql(irql); } NTSTATUS Unhook() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode); i++) { target[i] = oldcode[i]; } WPONx64(irql); return STATUS_SUCCESS; } NTSTATUS Hook() { KIRQL irql = WPOFFx64(); for (int i = 0; i < sizeof(newcode); i++) { target[i] = newcode[i]; } WPONx64(irql); return STATUS_SUCCESS; } PDRIVER_OBJECT g_Object = NULL; typedef struct _LDR_DATA_TABLE_ENTRY { LIST_ENTRY InLoadOrderLinks; LIST_ENTRY InMemoryOrderLinks; LIST_ENTRY InInitializationOrderLinks; PVOID DllBase; PVOID EntryPoint;//驱动的进入点 DriverEntry ULONG SizeOfImage; UNICODE_STRING FullDllName;//驱动的满路径 UNICODE_STRING BaseDllName;//不带路径的驱动名字 ULONG Flags; USHORT LoadCount; USHORT TlsIndex; union { LIST_ENTRY HashLinks; struct { PVOID SectionPointer; ULONG CheckSum; }; }; union { struct { ULONG TimeDateStamp; }; struct { PVOID LoadedImports; }; }; } LDR_DATA_TABLE_ENTRY, *PLDR_DATA_TABLE_ENTRY; typedef NTSTATUS (* FuncPtr) ( _In_ ULONG BugCheckCode, _In_ ULONG_PTR BugCheckParameter1, _In_ ULONG_PTR BugCheckParameter2, _In_ ULONG_PTR BugCheckParameter3, _In_ ULONG_PTR BugCheckParameter4 ); ULONG myKeBugCheckEx(_In_ ULONG BugCheckCode, _In_ ULONG_PTR BugCheckParameter1, _In_ ULONG_PTR BugCheckParameter2, _In_ ULONG_PTR BugCheckParameter3, _In_ ULONG_PTR BugCheckParameter4 ) { Unhook(); FuncPtr func = (FuncPtr)target; PVOID backtrace[MAX_BACKTRACE_DEPTH]; USHORT capturedFrames = RtlCaptureStackBackTrace(0, MAX_BACKTRACE_DEPTH, backtrace, NULL); for (USHORT i = 0; i < capturedFrames; i++) { kprintf(("xia0ji233:Backtrace[%u]: %p\n"), i, backtrace[i]); } kprintf(("calling KeBugCheckEx(%p,%p,%p,%p,%p)\n"),BugCheckCode,BugCheckParameter1,BugCheckParameter2,BugCheckParameter3,BugCheckParameter4); DbgBreakPoint(); LARGE_INTEGER inTime; inTime.QuadPart = (LONGLONG) - 10 * 1000 * 1000 * 3600; KeDelayExecutionThread(KernelMode, FALSE, &inTime); ULONG64 s = func(BugCheckCode,BugCheckParameter1,BugCheckParameter2,BugCheckParameter3,BugCheckParameter4); Hook(); return s; } MDLWriteMemory(PVOID pBaseAddress, PVOID pWriteData, SIZE_T writeDataSize) { PMDL pMdl = NULL; PVOID pNewAddress = NULL; pMdl = MmCreateMdl(NULL, pBaseAddress, writeDataSize); if (NULL == pMdl) { return FALSE; } MmBuildMdlForNonPagedPool(pMdl); pNewAddress = MmMapLockedPages(pMdl, KernelMode); if (NULL == pNewAddress) { IoFreeMdl(pMdl); } RtlCopyMemory(pNewAddress, pWriteData, writeDataSize); MmUnmapLockedPages(pNewAddress, pMdl); IoFreeMdl(pMdl); return TRUE; } void DriverUnload(PDRIVER_OBJECT pDriver) { kprintf(("Line %d:xia0ji233: start unload\n"), __LINE__); Unhook(); DeleteDevice(pDriver); } NTSTATUS DriverEntry( _In_ PDRIVER_OBJECT DriverObject, _In_ PUNICODE_STRING RegistryPath ) { DriverObject->DriverUnload = DriverUnload; kprintf(("Line %d:xia0ji233: RegistryPath = %S\n"), __LINE__, RegistryPath->Buffer); UNICODE_STRING unName = { 0 }; RtlInitUnicodeString(&unName, L"KeBugCheckEx"); target = ((ULONG64)MmGetSystemRoutineAddress(&unName))+5; kprintf(("Line %d:xia0ji233: KeBugCheckEx=%p\n"), __LINE__, target); g_Object = DriverObject; if (target) { for (int i = 0; i < sizeof(oldcode); i++) { oldcode[i] = target[i]; } *(UINT64*)(newcode + 2) = myKeBugCheckEx; Hook(); } else { kprintf(("xia0ji233:hahaha")); } return 0; }
这里去hook KeBugCheckEx，然后直接让它 sleep 一小时，防止它蓝我，我有更多时间可以去分析。
直接拿捏住了蓝屏。
在后面的分析中发现了 GameSec.exe 的内存一直在被读，估计是在搜索进程，然后读取进程的内存，这一部分后面没有分析太出来。
并且在运行的时候发现会读一些 exe 文件的字符串，在 shellcode 开头 + 80 的位置，这里后续没继续分析了。
编写一个search程序，在Load驱动运行后找到内核内存空间中的shellcode，输出shellcode范围内的任意地址
随后想到去dump shellcode，这里注册回调的方式并不能成功拦截住，因此想到直接去 hook，判断线程起始位置是否在模块范围内，或者说在 Loader.sys 范围内，如果有都输出然后调试器看看内存像不像shellcode，无果，于是选择去跟一下，结果跟到一个类似shellcode的地方（很多浮点指令，看起来像垃圾指令的混淆），dump下来用 010 分析。
方法1
通过内存地址的特征可以发现，前八位可以通过 VAD 的方式去获取，后四个位每次加载似乎都是固定的，因此只需要爆破两个字节用一个特征去匹配就行了，这里。
复制代码 隐藏代码#include "vad.h" #include <ntifs.h> #define kprintf(format, ...) DbgPrintEx(DPFLTR_IHVDRIVER_ID, DPFLTR_ERROR_LEVEL, format, ##__VA_ARGS__) // 定义VAD相对于EProcess头部偏移值 #define eprocess_offset_VadRoot 0x658 #define eprocess_offset_VadCount 0x668 VOID EnumVad(PMMVAD Root, PALL_VADS pBuffer, ULONG nCnt) { if (!Root || !pBuffer || !nCnt) { return; } __try { if (nCnt > pBuffer->nCnt) { // 得到起始页与结束页 ULONG64 endptr = (ULONG64)Root->Core.EndingVpnHigh; endptr = endptr << 32; ULONG64 startptr = (ULONG64)Root->Core.StartingVpnHigh; startptr = startptr << 32; // 得到根节点 pBuffer->VadInfos[pBuffer->nCnt].pVad = (ULONG_PTR)Root; // 起始页: startingVpn * 0x1000 pBuffer->VadInfos[pBuffer->nCnt].startVpn = (startptr | Root->Core.StartingVpn) << PAGE_SHIFT; // 结束页: EndVpn * 0x1000 + 0xfff pBuffer->VadInfos[pBuffer->nCnt].endVpn = ((endptr | Root->Core.EndingVpn) << PAGE_SHIFT) + 0xfff; // VAD标志 928 = Mapped 1049088 = Private .... pBuffer->VadInfos[pBuffer->nCnt].flags = Root->Core.u1.Flags.flag; // 验证节点可读性 if (MmIsAddressValid(Root->Subsection) && MmIsAddressValid(Root->Subsection->ControlArea)) { if (MmIsAddressValid((PVOID)((Root->Subsection->ControlArea->FilePointer.Value >> 4) << 4))) { pBuffer->VadInfos[pBuffer->nCnt].pFileObject = ((Root->Subsection->ControlArea->FilePointer.Value >> 4) << 4); } } pBuffer->nCnt++; } if (MmIsAddressValid(Root->Core.VadNode.Left)) { // 递归枚举左子树 EnumVad((PMMVAD)Root->Core.VadNode.Left, pBuffer, nCnt); } if (MmIsAddressValid(Root->Core.VadNode.Right)) { // 递归枚举右子树 EnumVad((PMMVAD)Root->Core.VadNode.Right, pBuffer, nCnt); } } __except (1) { } } BOOLEAN EnumProcessVad(ULONG Pid, PALL_VADS pBuffer, ULONG nCnt) { PEPROCESS Peprocess = 0; PRTL_AVL_TREE Table = NULL; PMMVAD Root = NULL; // 通过进程PID得到进程EProcess if (NT_SUCCESS(PsLookupProcessByProcessId((HANDLE)Pid, &Peprocess))) { // 与偏移相加得到VAD头节点 Table = (PRTL_AVL_TREE)((UCHAR*)Peprocess + eprocess_offset_VadRoot); if (!MmIsAddressValid(Table) || !eprocess_offset_VadRoot) { return FALSE; } __try { // 取出头节点 Root = (PMMVAD)Table->Root; if (nCnt > pBuffer->nCnt) { // 得到起始页与结束页 ULONG64 endptr = (ULONG64)Root->Core.EndingVpnHigh; endptr = endptr << 32; ULONG64 startptr = (ULONG64)Root->Core.StartingVpnHigh; startptr = startptr << 32; pBuffer->VadInfos[pBuffer->nCnt].pVad = (ULONG_PTR)Root; // 起始页: startingVpn * 0x1000 pBuffer->VadInfos[pBuffer->nCnt].startVpn = (startptr | Root->Core.StartingVpn) << PAGE_SHIFT; // 结束页: EndVpn * 0x1000 + 0xfff pBuffer->VadInfos[pBuffer->nCnt].endVpn = (endptr | Root->Core.EndingVpn) << PAGE_SHIFT; pBuffer->VadInfos[pBuffer->nCnt].flags = Root->Core.u1.Flags.flag; if (MmIsAddressValid(Root->Subsection) && MmIsAddressValid(Root->Subsection->ControlArea)) { if (MmIsAddressValid((PVOID)((Root->Subsection->ControlArea->FilePointer.Value >> 4) << 4))) { pBuffer->VadInfos[pBuffer->nCnt].pFileObject = ((Root->Subsection->ControlArea->FilePointer.Value >> 4) << 4); } } pBuffer->nCnt++; } // 枚举左子树 if (Table->Root->Left) { EnumVad((MMVAD*)Table->Root->Left, pBuffer, nCnt); } // 枚举右子树 if (Table->Root->Right) { EnumVad((MMVAD*)Table->Root->Right, pBuffer, nCnt); } } __finally { ObDereferenceObject(Peprocess); } } else { return FALSE; } return TRUE; } VOID UnDriver(PDRIVER_OBJECT driver) { kprintf(("unload\n")); } NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath) { kprintf(("hello xia0ji233\n")); typedef struct { ULONG nPid; ULONG nSize; PALL_VADS pBuffer; }VADProcess; __try { VADProcess vad = { 0 }; vad.nPid = 4; // 默认有1000个线程 vad.nSize = sizeof(VAD_INFO) * 0x5000 + sizeof(ULONG); // 分配临时空间 vad.pBuffer = (PALL_VADS)ExAllocatePool(PagedPool, vad.nSize); // 根据传入长度得到枚举数量 ULONG nCount = (vad.nSize - sizeof(ULONG)) / sizeof(VAD_INFO); // 枚举VAD EnumProcessVad(vad.nPid, vad.pBuffer, nCount); uintptr_t addr; for (ULONG64 i = 0x0; i <65536; i++) { addr = vad.pBuffer->VadInfos[0].pVad & 0xffffffff00000000; addr = addr + 0x1000; addr = addr + (i<<16); if (MmIsAddressValid((PVOID)addr) && *((ULONG64 *)addr) == 0x7C8B483024748B48 ) { kprintf(("shellcode found in %p\n"), addr); //DbgBreakPoint(); goto end; } } } __except (1) { kprintf(("Something Error1\n")); } end: Driver->DriverUnload = UnDriver; return STATUS_SUCCESS; }
vad.h
复制代码 隐藏代码#pragma once #include <ntifs.h> typedef struct _MM_GRAPHICS_VAD_FLAGS // 15 elements, 0x4 bytes (sizeof) { /*0x000*/ ULONG32 Lock : 1; // 0 BitPosition /*0x000*/ ULONG32 LockContended : 1; // 1 BitPosition /*0x000*/ ULONG32 DeleteInProgress : 1; // 2 BitPosition /*0x000*/ ULONG32 NoChange : 1; // 3 BitPosition /*0x000*/ ULONG32 VadType : 3; // 4 BitPosition /*0x000*/ ULONG32 Protection : 5; // 7 BitPosition /*0x000*/ ULONG32 PreferredNode : 6; // 12 BitPosition /*0x000*/ ULONG32 PageSize : 2; // 18 BitPosition /*0x000*/ ULONG32 PrivateMemoryAlwaysSet : 1; // 20 BitPosition /*0x000*/ ULONG32 WriteWatch : 1; // 21 BitPosition /*0x000*/ ULONG32 FixedLargePageSize : 1; // 22 BitPosition /*0x000*/ ULONG32 ZeroFillPagesOptional : 1; // 23 BitPosition /*0x000*/ ULONG32 GraphicsAlwaysSet : 1; // 24 BitPosition /*0x000*/ ULONG32 GraphicsUseCoherentBus : 1; // 25 BitPosition /*0x000*/ ULONG32 GraphicsPageProtection : 3; // 26 BitPosition }MM_GRAPHICS_VAD_FLAGS, * PMM_GRAPHICS_VAD_FLAGS; typedef struct _MM_PRIVATE_VAD_FLAGS // 15 elements, 0x4 bytes (sizeof) { /*0x000*/ ULONG32 Lock : 1; // 0 BitPosition /*0x000*/ ULONG32 LockContended : 1; // 1 BitPosition /*0x000*/ ULONG32 DeleteInProgress : 1; // 2 BitPosition /*0x000*/ ULONG32 NoChange : 1; // 3 BitPosition /*0x000*/ ULONG32 VadType : 3; // 4 BitPosition /*0x000*/ ULONG32 Protection : 5; // 7 BitPosition /*0x000*/ ULONG32 PreferredNode : 6; // 12 BitPosition /*0x000*/ ULONG32 PageSize : 2; // 18 BitPosition /*0x000*/ ULONG32 PrivateMemoryAlwaysSet : 1; // 20 BitPosition /*0x000*/ ULONG32 WriteWatch : 1; // 21 BitPosition /*0x000*/ ULONG32 FixedLargePageSize : 1; // 22 BitPosition /*0x000*/ ULONG32 ZeroFillPagesOptional : 1; // 23 BitPosition /*0x000*/ ULONG32 Graphics : 1; // 24 BitPosition /*0x000*/ ULONG32 Enclave : 1; // 25 BitPosition /*0x000*/ ULONG32 ShadowStack : 1; // 26 BitPosition }MM_PRIVATE_VAD_FLAGS, * PMM_PRIVATE_VAD_FLAGS; typedef struct _MMVAD_FLAGS // 9 elements, 0x4 bytes (sizeof) { /*0x000*/ ULONG32 Lock : 1; // 0 BitPosition /*0x000*/ ULONG32 LockContended : 1; // 1 BitPosition /*0x000*/ ULONG32 DeleteInProgress : 1; // 2 BitPosition /*0x000*/ ULONG32 NoChange : 1; // 3 BitPosition /*0x000*/ ULONG32 VadType : 3; // 4 BitPosition /*0x000*/ ULONG32 Protection : 5; // 7 BitPosition /*0x000*/ ULONG32 PreferredNode : 6; // 12 BitPosition /*0x000*/ ULONG32 PageSize : 2; // 18 BitPosition /*0x000*/ ULONG32 PrivateMemory : 1; // 20 BitPosition }MMVAD_FLAGS, * PMMVAD_FLAGS; typedef struct _MM_SHARED_VAD_FLAGS // 11 elements, 0x4 bytes (sizeof) { /*0x000*/ ULONG32 Lock : 1; // 0 BitPosition /*0x000*/ ULONG32 LockContended : 1; // 1 BitPosition /*0x000*/ ULONG32 DeleteInProgress : 1; // 2 BitPosition /*0x000*/ ULONG32 NoChange : 1; // 3 BitPosition /*0x000*/ ULONG32 VadType : 3; // 4 BitPosition /*0x000*/ ULONG32 Protection : 5; // 7 BitPosition /*0x000*/ ULONG32 PreferredNode : 6; // 12 BitPosition /*0x000*/ ULONG32 PageSize : 2; // 18 BitPosition /*0x000*/ ULONG32 PrivateMemoryAlwaysClear : 1; // 20 BitPosition /*0x000*/ ULONG32 PrivateFixup : 1; // 21 BitPosition /*0x000*/ ULONG32 HotPatchAllowed : 1; // 22 BitPosition }MM_SHARED_VAD_FLAGS, * PMM_SHARED_VAD_FLAGS; typedef struct _MMVAD_FLAGS2 // 7 elements, 0x4 bytes (sizeof) { /*0x000*/ ULONG32 FileOffset : 24; // 0 BitPosition /*0x000*/ ULONG32 Large : 1; // 24 BitPosition /*0x000*/ ULONG32 TrimBehind : 1; // 25 BitPosition /*0x000*/ ULONG32 Inherit : 1; // 26 BitPosition /*0x000*/ ULONG32 NoValidationNeeded : 1; // 27 BitPosition /*0x000*/ ULONG32 PrivateDemandZero : 1; // 28 BitPosition /*0x000*/ ULONG32 Spare : 3; // 29 BitPosition }MMVAD_FLAGS2, * PMMVAD_FLAGS2; typedef struct _MMVAD_SHORT { RTL_BALANCED_NODE VadNode; UINT32 StartingVpn; /*0x18*/ UINT32 EndingVpn; /*0x01C*/ UCHAR StartingVpnHigh; UCHAR EndingVpnHigh; UCHAR CommitChargeHigh; UCHAR SpareNT64VadUChar; INT32 ReferenceCount; EX_PUSH_LOCK PushLock; /*0x028*/ struct { union { ULONG_PTR flag; MM_PRIVATE_VAD_FLAGS PrivateVadFlags; /*0x030*/ MMVAD_FLAGS VadFlags; MM_GRAPHICS_VAD_FLAGS GraphicsVadFlags; MM_SHARED_VAD_FLAGS SharedVadFlags; }Flags; }u1; PVOID EventList; /*0x038*/ }MMVAD_SHORT, * PMMVAD_SHORT; typedef struct _MMADDRESS_NODE { ULONG64 u1; struct _MMADDRESS_NODE* LeftChild; struct _MMADDRESS_NODE* RightChild; ULONG64 StartingVpn; ULONG64 EndingVpn; }MMADDRESS_NODE, * PMMADDRESS_NODE; typedef struct _MMEXTEND_INFO // 2 elements, 0x10 bytes (sizeof) { /*0x000*/ UINT64 CommittedSize; /*0x008*/ ULONG32 ReferenceCount; /*0x00C*/ UINT8 _PADDING0_[0x4]; }MMEXTEND_INFO, * PMMEXTEND_INFO; struct _SEGMENT { struct _CONTROL_AREA* ControlArea; ULONG TotalNumberOfPtes; ULONG SegmentFlags; ULONG64 NumberOfCommittedPages; ULONG64 SizeOfSegment; union { struct _MMEXTEND_INFO* ExtendInfo; void* BasedAddress; }u; ULONG64 SegmentLock; ULONG64 u1; ULONG64 u2; PVOID* PrototypePte; ULONGLONG ThePtes[0x1]; }; typedef struct _EX_FAST_REF { union { PVOID Object; ULONG_PTR RefCnt : 3; ULONG_PTR Value; }; } EX_FAST_REF, * PEX_FAST_REF; typedef struct _CONTROL_AREA // 17 elements, 0x80 bytes (sizeof) { /*0x000*/ struct _SEGMENT* Segment; union // 2 elements, 0x10 bytes (sizeof) { /*0x008*/ struct _LIST_ENTRY ListHead; // 2 elements, 0x10 bytes (sizeof) /*0x008*/ VOID* AweContext; }; /*0x018*/ UINT64 NumberOfSectionReferences; /*0x020*/ UINT64 NumberOfPfnReferences; /*0x028*/ UINT64 NumberOfMappedViews; /*0x030*/ UINT64 NumberOfUserReferences; /*0x038*/ ULONG32 u; // 2 elements, 0x4 bytes (sizeof) /*0x03C*/ ULONG32 u1; // 2 elements, 0x4 bytes (sizeof) /*0x040*/ struct _EX_FAST_REF FilePointer; // 3 elements, 0x8 bytes (sizeof) // 4 elements, 0x8 bytes (sizeof) }CONTROL_AREA, * PCONTROL_AREA; typedef struct _SUBSECTION_ { struct _CONTROL_AREA* ControlArea; }SUBSECTION, * PSUBSECTION; typedef struct _MMVAD { MMVAD_SHORT Core; union /*0x040*/ { UINT32 LongFlags2; //现在用不到省略 MMVAD_FLAGS2 VadFlags2; }u2; PSUBSECTION Subsection; /*0x048*/ PVOID FirstPrototypePte; /*0x050*/ PVOID LastContiguousPte; /*0x058*/ LIST_ENTRY ViewLinks; /*0x060*/ PEPROCESS VadsProcess; /*0x070*/ PVOID u4; /*0x078*/ PVOID FileObject; /*0x080*/ }MMVAD, * PMMVAD; typedef struct _RTL_AVL_TREE // 1 elements, 0x8 bytes (sizeof) { /*0x000*/ struct _RTL_BALANCED_NODE* Root; }RTL_AVL_TREE, * PRTL_AVL_TREE; typedef struct _VAD_INFO_ { ULONG_PTR pVad; ULONG_PTR startVpn; ULONG_PTR endVpn; ULONG_PTR pFileObject; ULONG_PTR flags; }VAD_INFO, * PVAD_INFO; typedef struct _ALL_VADS_ { ULONG nCnt; VAD_INFO VadInfos[1]; }ALL_VADS, * PALL_VADS; typedef struct _MMSECTION_FLAGS // 27 elements, 0x4 bytes (sizeof) { /*0x000*/ UINT32 BeingDeleted : 1; // 0 BitPosition /*0x000*/ UINT32 BeingCreated : 1; // 1 BitPosition /*0x000*/ UINT32 BeingPurged : 1; // 2 BitPosition /*0x000*/ UINT32 NoModifiedWriting : 1; // 3 BitPosition /*0x000*/ UINT32 FailAllIo : 1; // 4 BitPosition /*0x000*/ UINT32 Image : 1; // 5 BitPosition /*0x000*/ UINT32 Based : 1; // 6 BitPosition /*0x000*/ UINT32 File : 1; // 7 BitPosition /*0x000*/ UINT32 AttemptingDelete : 1; // 8 BitPosition /*0x000*/ UINT32 PrefetchCreated : 1; // 9 BitPosition /*0x000*/ UINT32 PhysicalMemory : 1; // 10 BitPosition /*0x000*/ UINT32 ImageControlAreaOnRemovableMedia : 1; // 11 BitPosition /*0x000*/ UINT32 Reserve : 1; // 12 BitPosition /*0x000*/ UINT32 Commit : 1; // 13 BitPosition /*0x000*/ UINT32 NoChange : 1; // 14 BitPosition /*0x000*/ UINT32 WasPurged : 1; // 15 BitPosition /*0x000*/ UINT32 UserReference : 1; // 16 BitPosition /*0x000*/ UINT32 GlobalMemory : 1; // 17 BitPosition /*0x000*/ UINT32 DeleteOnClose : 1; // 18 BitPosition /*0x000*/ UINT32 FilePointerNull : 1; // 19 BitPosition /*0x000*/ ULONG32 PreferredNode : 6; // 20 BitPosition /*0x000*/ UINT32 GlobalOnlyPerSession : 1; // 26 BitPosition /*0x000*/ UINT32 UserWritable : 1; // 27 BitPosition /*0x000*/ UINT32 SystemVaAllocated : 1; // 28 BitPosition /*0x000*/ UINT32 PreferredFsCompressionBoundary : 1; // 29 BitPosition /*0x000*/ UINT32 UsingFileExtents : 1; // 30 BitPosition /*0x000*/ UINT32 PageSize64K : 1; // 31 BitPosition }MMSECTION_FLAGS, * PMMSECTION_FLAGS; typedef struct _SECTION // 9 elements, 0x40 bytes (sizeof) { /*0x000*/ struct _RTL_BALANCED_NODE SectionNode; // 6 elements, 0x18 bytes (sizeof) /*0x018*/ UINT64 StartingVpn; /*0x020*/ UINT64 EndingVpn; /*0x028*/ union { PCONTROL_AREA ControlArea; PVOID FileObject; }u1; // 4 elements, 0x8 bytes (sizeof) /*0x030*/ UINT64 SizeOfSection; /*0x038*/ union { ULONG32 LongFlags; MMSECTION_FLAGS Flags; }u; // 2 elements, 0x4 bytes (sizeof) struct // 3 elements, 0x4 bytes (sizeof) { /*0x03C*/ ULONG32 InitialPageProtection : 12; // 0 BitPosition /*0x03C*/ ULONG32 SessionId : 19; // 12 BitPosition /*0x03C*/ ULONG32 NoValidationNeeded : 1; // 31 BitPosition }; }SECTION, * PSECTION;
先加载 loader 再加载 search，成功输出 shellcode 的地址，特征码匹配前八个字节，在自己的环境只输出了一个地址，如果输出多个地址可以考虑加长特征码。
方法2
通过获取到线程结构得到它的线程上下文，输出 RIP 的值应该也行，通过PCHUNTER看到shellcode运行的线程
通过分析可知 shellcode 执行的线程具有如下特点：
与 TID=12 的线程入口相同
保持运行状态
据此可以筛选得到这个线程，通过线程结构体可以找到它的栈
多次运行发现栈中存在 GameSec.exe 这个字符串。并且在它 - 0x28 的位置有一个地址，那个地址前八位和shellcode一致，所以同样可以爆破+特征码匹配。
复制代码 隐藏代码#include<ntifs.h> #include <ntddk.h> #include <ntstrsafe.h> #define kprintf(format, ...) DbgPrintEx(DPFLTR_IHVDRIVER_ID, DPFLTR_ERROR_LEVEL, format, ##__VA_ARGS__) #define MAX_BACKTRACE_DEPTH 20 ULONG64 num = 0; NTSTATUS EnumerateKernelThreads(); typedef NTSTATUS (*ZWQUERYSYSTEMINFORMATION)(ULONG, PVOID, ULONG, PULONG); VOID DRIVERUNLOAD(_In_ struct _DRIVER_OBJECT* DriverObject) { kprintf(("unload\n")); } NTSTATUS EnumerateKernelThreads() { PETHREAD T12 = NULL; PETHREAD T; PsLookupThreadByThreadId(12, &T12); kprintf(("T12=%p\n"), T12); ULONG64 Start = *(ULONG64 *)((ULONG64)T12 + 0x620); HANDLE TargetThread = 0; for (int i = 16; i < 0x20000; i+=4) { T = NULL; PsLookupThreadByThreadId(i, &T); if (T) { ULONG64 Startaddr = *(ULONG64 *)((ULONG64)T + 0x620); if (Startaddr == Start) { kprintf(("Found Thread=%p pThread=%p\n"), i,T); TargetThread = i; break; } } } if (T != NULL) { ULONG64 StackBase = 0; ULONG64 StackLimit = 0; StackBase= *(ULONG64 *)((ULONG64)T + 0x38); StackLimit=*(ULONG64 *)((ULONG64)T + 0x30); kprintf(("Stackbase=%p StackLimit=%p\n"), StackBase, StackLimit); for (ULONG64 addr = StackBase-0x10 ; addr > StackLimit; addr -= 8) { if (!strcmp(addr, "GameSec.exe")) { kprintf(("Found string in %p\n"), addr); uintptr_t address; for (ULONG64 i = 0x0; i <65536; i++) { address = (*(ULONG64*)(addr-0x28)) & 0xffffffff00000000; address = address + 0x1000; address = address + (i<<16); if (MmIsAddressValid((PVOID)address) && *((ULONG64 *)address) == 0x7C8B483024748B48 ) { kprintf(("shellcode found in %p\n"), address); //DbgBreakPoint(); break; } } break; } } } return STATUS_SUCCESS; } NTSTATUS DriverEntry(PDRIVER_OBJECT pDriver, PUNICODE_STRING pReg) { kprintf(("hello xia0ji233\n")); EnumerateKernelThreads(); pDriver->DriverUnload = DRIVERUNLOAD; return STATUS_SUCCESS; }
先运行 Loader.sys，再运行EmurateThread.sys，可以成功输出shellcode的地址。
方法3
随后我发现线程结构体中的 TrapFrame 有点东西，通过一段时间的运行之后，发现它的一些寄存器中会带上点东西
这里我选 Rdx，取前8位，暴力搜索4位（65536，可接受范围内）匹配。
先运行 Loader.sys 再运行 Search3.sys，可以直接得到 shellcode 的地址。
方法4
观察到 ETHTREAD 结构体中有个指针指向了距离shellcode比较近的位置
获取这个指针的前八位，然后爆破，匹配特征码。
先运行Loader.sys，再运行 Search4.sys，即可获得shellcode的地址。
方法5
挂起线程，此时会将线程上下文保存在栈顶中，再去遍历一遍栈，获得RIP指针，这里判断只需要拿 RSP 即可，当 [addr+0x180]-0x400==addr（+0x180是RSP相对于上下文结构体的偏移，0x400是context上下文大小）时，取出 RIP 即可。
先运行 Loader.sys，在运行search5.sys，即可输出shellcode。
-官方论坛
👆👆👆
公众号设置“星标”，您不会错过新的消息通知
如开放注册、精华文章和周边活动等公告
