驱动开发：内核CR3切换读写内存
首先CR3是什么，CR3是一个寄存器，该寄存器内保存有页目录表物理地址(PDBR地址)，其实CR3内部存放的就是页目录表的内存基地址，运用CR3切换可实现对特定进程内存地址的强制读写操作，此类读写属于有痕读写，多数驱动保护都会将这个地址改为无效，此时CR3读写就失效了，当然如果能找到CR3的正确地址，此方式也是靠谱的一种读写机制。
在读写进程之前需要先找到进程的PEPROCESS结构，查找结构的方法也很简单，依次遍历进程并对比进程名称即可得到。
#include <ntifs.h>
#include <windef.h>
#include <intrin.h>
NTKERNELAPI NTSTATUS PsLookupProcessByProcessId(HANDLE ProcessId, PEPROCESS *Process);
NTKERNELAPI CHAR* PsGetProcessImageFileName(PEPROCESS Process);
// 定义全局EProcess结构
PEPROCESS Global_Peprocess = NULL;
// 根据进程名获得EPROCESS结构
NTSTATUS GetProcessObjectByName(char *name)
{
NTSTATUS Status = STATUS_UNSUCCESSFUL;
SIZE_T i;
__try
{
for (i = 100; i<20000; i += 4)
{
NTSTATUS st;
PEPROCESS ep;
st = PsLookupProcessByProcessId((HANDLE)i, &ep);
if (NT_SUCCESS(st))
{
char *pn = PsGetProcessImageFileName(ep);
if (_stricmp(pn, name) == 0)
{
Global_Peprocess = ep;
}
}
}
}
__except (EXCEPTION_EXECUTE_HANDLER)
{
return Status;
}
return Status;
}
VOID UnDriver(PDRIVER_OBJECT driver)
{
DbgPrint(("Uninstall Driver Is OK \n"));
}
NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
DbgPrint("hello lyshark \n");
NTSTATUS nt = GetProcessObjectByName("Tutorial-i386.exe");
if (NT_SUCCESS(nt))
{
DbgPrint("[+] eprocess = %x \n", Global_Peprocess);
}
Driver->DriverUnload = UnDriver;
return STATUS_SUCCESS;
}以打开Tutorial-i386.exe为例，打开后即可返回他的Proces，当然也可以直接传入进程PID同样可以得到进程Process结构地址。
// 根据PID打开进程
PEPROCESS Peprocess = NULL;
DWORD PID = 6672;
NTSTATUS nt = PsLookupProcessByProcessId((HANDLE)PID, &Peprocess);通过CR3读取内存实现代码如下，我们读取Tutorial-i386.exe里面的0x0009EDC8这段内存，读出长度是4字节，代码如下。
#include <ntifs.h>
#include <windef.h>
#include <intrin.h>
#define DIRECTORY_TABLE_BASE 0x028
#pragma intrinsic(_disable)
#pragma intrinsic(_enable)
NTKERNELAPI NTSTATUS PsLookupProcessByProcessId(HANDLE ProcessId, PEPROCESS *Process);
NTKERNELAPI CHAR* PsGetProcessImageFileName(PEPROCESS Process);
// 关闭写保护
KIRQL Open()
{
KIRQL irql = KeRaiseIrqlToDpcLevel();
UINT64 cr0 = __readcr0();
cr0 &= 0xfffffffffffeffff;
__writecr0(cr0);
_disable();
return irql;
}
// 开启写保护
void Close(KIRQL irql)
{
UINT64 cr0 = __readcr0();
cr0 |= 0x10000;
_enable();
__writecr0(cr0);
KeLowerIrql(irql);
}
// 检查内存
ULONG64 CheckAddressVal(PVOID p)
{
if (MmIsAddressValid(p) == FALSE)
return 0;
return *(PULONG64)p;
}
// CR3 寄存器读内存
BOOLEAN CR3_ReadProcessMemory(IN PEPROCESS Process, IN PVOID Address, IN UINT32 Length, OUT PVOID Buffer)
{
ULONG64 pDTB = 0, OldCr3 = 0, vAddr = 0;
pDTB = CheckAddressVal((UCHAR*)Process + DIRECTORY_TABLE_BASE);
if (pDTB == 0)
{
return FALSE;
}
_disable();
OldCr3 = __readcr3();
__writecr3(pDTB);
_enable();
if (MmIsAddressValid(Address))
{
RtlCopyMemory(Buffer, Address, Length);
DbgPrint("读入数据: %ld", *(PDWORD)Buffer);
return TRUE;
}
_disable();
__writecr3(OldCr3);
_enable();
return FALSE;
}
VOID UnDriver(PDRIVER_OBJECT driver)
{
DbgPrint(("Uninstall Driver Is OK \n"));
}
NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
DbgPrint("hello lyshark \n");
// 根据PID打开进程
PEPROCESS Peprocess = NULL;
DWORD PID = 6672;
NTSTATUS nt = PsLookupProcessByProcessId((HANDLE)PID, &Peprocess);
DWORD buffer = 0;
BOOLEAN bl = CR3_ReadProcessMemory(Peprocess, (PVOID)0x0009EDC8, 4, &buffer);
DbgPrint("readbuf = %x \n", buffer);
DbgPrint("readbuf = %d \n", buffer);
Driver->DriverUnload = UnDriver;
return STATUS_SUCCESS;
}读出后输出效果如下：
写出内存与读取基本一致，代码如下。
#include <ntifs.h>
#include <windef.h>
#include <intrin.h>
#define DIRECTORY_TABLE_BASE 0x028
#pragma intrinsic(_disable)
#pragma intrinsic(_enable)
NTKERNELAPI NTSTATUS PsLookupProcessByProcessId(HANDLE ProcessId, PEPROCESS *Process);
NTKERNELAPI CHAR* PsGetProcessImageFileName(PEPROCESS Process);
// 关闭写保护
KIRQL Open()
{
KIRQL irql = KeRaiseIrqlToDpcLevel();
UINT64 cr0 = __readcr0();
cr0 &= 0xfffffffffffeffff;
__writecr0(cr0);
_disable();
return irql;
}
// 开启写保护
void Close(KIRQL irql)
{
UINT64 cr0 = __readcr0();
cr0 |= 0x10000;
_enable();
__writecr0(cr0);
KeLowerIrql(irql);
}
// 检查内存
ULONG64 CheckAddressVal(PVOID p)
{
if (MmIsAddressValid(p) == FALSE)
return 0;
return *(PULONG64)p;
}
// CR3 寄存器写内存
BOOLEAN CR3_WriteProcessMemory(IN PEPROCESS Process, IN PVOID Address, IN UINT32 Length, IN PVOID Buffer)
{
ULONG64 pDTB = 0, OldCr3 = 0, vAddr = 0;
// 检查内存
pDTB = CheckAddressVal((UCHAR*)Process + DIRECTORY_TABLE_BASE);
if (pDTB == 0)
{
return FALSE;
}
_disable();
// 读取CR3
OldCr3 = __readcr3();
// 写CR3
__writecr3(pDTB);
_enable();
// 验证并拷贝内存
if (MmIsAddressValid(Address))
{
RtlCopyMemory(Address, Buffer, Length);
return TRUE;
}
_disable();
// 恢复CR3
__writecr3(OldCr3);
_enable();
return FALSE;
}
VOID UnDriver(PDRIVER_OBJECT driver)
{
DbgPrint(("Uninstall Driver Is OK \n"));
}
NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
DbgPrint("hello lyshark \n");
// 根据PID打开进程
PEPROCESS Peprocess = NULL;
DWORD PID = 6672;
NTSTATUS nt = PsLookupProcessByProcessId((HANDLE)PID, &Peprocess);
DWORD buffer = 999;
BOOLEAN bl = CR3_WriteProcessMemory(Peprocess, (PVOID)0x0009EDC8, 4, &buffer);
DbgPrint("写出状态: %d \n", bl);
Driver->DriverUnload = UnDriver;
return STATUS_SUCCESS;
}写出后效果如下：
至于进程将CR3改掉了读取不到该寄存器该如何处理，这里我找到了一段参考代码，可以实现寻找CR3地址这个功能。
#include <ntddk.h>
#include <ntstrsafe.h>
#include <windef.h>
#include <intrin.h>
#pragma pack(push, 1)
typedef struct _IDTR // IDT基址
{
USHORT limit; // 范围 占8位
ULONG64 base; // 基地址 占32位 _IDT_ENTRY类型指针
}IDTR, *PIDTR;
typedef union _IDT_ENTRY
{
struct kidt
{
USHORT OffsetLow;
USHORT Selector;
USHORT IstIndex : 3;
USHORT Reserved0 : 5;
USHORT Type : 5;
USHORT Dpl : 2;
USHORT Present : 1;
USHORT OffsetMiddle;
ULONG OffsetHigh;
ULONG Reserved1;
}idt;
UINT64 Alignment;
} IDT_ENTRY, *PIDT_ENTRY;
#pragma pack(pop)
// 输出调试内容
void DebugPrint(const char* fmt, ...)
{
UNREFERENCED_PARAMETER(fmt);
va_list ap;
va_start(ap, fmt);
vDbgPrintEx(DPFLTR_IHVDRIVER_ID, DPFLTR_ERROR_LEVEL, fmt, ap);
va_end(ap);
return;
}
// 获取IDT表地址
ULONG64 GetIdtAddr(ULONG64 pIdtBaseAddr, UCHAR pIndex)
{
PIDT_ENTRY Pidt_info = (PIDT_ENTRY)(pIdtBaseAddr);
Pidt_info += pIndex;
ULONG64 vCurrentAddr = 0;
ULONG64 vCurrentHighAddr = 0;
vCurrentAddr = Pidt_info->idt.OffsetMiddle;
vCurrentAddr = vCurrentAddr << 16;
vCurrentAddr += Pidt_info->idt.OffsetLow;
vCurrentHighAddr = Pidt_info->idt.OffsetHigh;
vCurrentHighAddr = vCurrentHighAddr << 32;
vCurrentAddr += vCurrentHighAddr;
return vCurrentAddr;
}
VOID UnLoadDriver()
{
}
NTSTATUS DriverEntry(_In_ PDRIVER_OBJECT pPDriverObj, _In_ PUNICODE_STRING pRegistryPath)
{
UNREFERENCED_PARAMETER(pRegistryPath);
pPDriverObj->DriverUnload = (PDRIVER_UNLOAD)UnLoadDriver;
/**
TP版KiPageFault
fffff880`09f54000 50 push rax
// 这里实际上是真实处理函数的地址 需要 & 0xFFFFFFFFFFF00000
fffff880`09f54001 48b87830ce0980f8ffff mov rax,0FFFFF88009CE3078h
fffff880`09f5400b 4883ec08 sub rsp,8
fffff880`09f5400f 48890424 mov qword ptr [rsp],rax
fffff880`09f54013 48311424 xor qword ptr [rsp],rdx
fffff880`09f54017 e810000000 call fffff880`09f5402c
fffff880`09f5401c 896eff mov dword ptr [rsi-1],ebp
fffff880`09f5401f 230500000089 and eax,dword ptr [fffff87f`92f54025]
**/
//得到TP KiPageFault地址
// _IDTR vContent;
// __sidt(&vContent);
ULONG64 vTpKiPageFault = GetIdtAddr(vContent.base, 0xE);
//得到TP 动态内存起始值
ULONG64 vTpMemory = *(PULONG64)(vTpKiPageFault + 0x3) & 0xFFFFFFFFFFF00000;
//得到TP KiPageFault真实处理函数
ULONG64 vTpKiPageFaultFuncAddr = vTpMemory + 0x4CE7C;
if (MmIsAddressValid((PVOID)vTpKiPageFaultFuncAddr))
{//真实处理函数有效
//得到TP数据对象基地址
ULONG64 vTpDataObjectBase = *(PULONG)(vTpMemory + 0x1738B) + vTpMemory + 0x1738F;
if (MmIsAddressValid((PVOID)vTpDataObjectBase))
{//基地址有效
//得到TP 用来保存真实CR3 保存当前所属进程ID 的对象
ULONG64 vTpDataObject = *(PULONG64)vTpDataObjectBase;
DebugPrint("数据对象:0x%016llx, 真实CR3:0x%016llx, 所属进程ID:%d\n", vTpDataObject, *(PULONG64)(vTpDataObject + 0x70), *(PULONG)(vTpDataObject + 0x18));
}
else
DebugPrint("vTpDataObjectBase无法读取:0x%016llx\n", vTpDataObjectBase);
}
else
DebugPrint("vTpKiPageFaultFuncAddr无法读取:0x%016llx\n", vTpKiPageFaultFuncAddr);
return STATUS_SUCCESS;
}手机扫一扫
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