Api_hook 拦截 messageBox 等函数

library hookdll;

uses
  SysUtils,
  Windows,
  Classes,
  unitHook in 'unitHook.pas';

{$R *.res}

const
  HOOK_MEM_FILENAME  =  'tmp.hkt';

var
  hhk: HHOOK;
  Hook: array[..] of TNtHookClass;

//内存映射
  MemFile: THandle;
  startPid: PDWORD;   //保存PID

{--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--}

//拦截 MessageBoxA
function NewMessageBoxA(_hWnd: HWND; lpText,
 lpCaption: PAnsiChar; uType: UINT): Integer; stdcall;
type
  TNewMessageBoxA = function (_hWnd: HWND; lpText,
lpCaption: PAnsiChar; uType: UINT): Integer; stdcall;
begin
  lpText := PAnsiChar('已经被拦截 MessageBoxA');
  Hook[].UnHook;
Result := TNewMessageBoxA(Hook[].BaseAddr)(_hWnd, lpText, lpCaption, uType);
  Hook[].Hook;
end;

//拦截 MessageBoxW
function NewMessageBoxW(_hWnd: HWND; lpText,
lpCaption: PWideChar; uType: UINT): Integer; stdcall;
type
  TNewMessageBoxW = function (_hWnd: HWND; lpText,
lpCaption: PWideChar; uType: UINT): Integer; stdcall;
begin
  lpText := '已经被拦截 MessageBoxW';
  Hook[].UnHook;
Result := TNewMessageBoxW(Hook[].BaseAddr)(_hWnd, lpText, lpCaption, uType);
  Hook[].Hook;
end;

//拦截 MessageBeep
function NewMessageBeep(uType: UINT): BOOL; stdcall;
type
  TNewMessageBeep = function (uType: UINT): BOOL; stdcall;
begin
Result := True;
end;

//拦截 OpenProcess , 防止关闭
function NewOpenProcess(dwDesiredAccess: DWORD;
 bInheritHandle: BOOL; dwProcessId: DWORD): THandle; stdcall;
type
  TNewOpenProcess = function (dwDesiredAccess: DWORD;
bInheritHandle: BOOL; dwProcessId: DWORD): THandle; stdcall;
begin
  if startPid^ = dwProcessId  then
  begin
    result := ;
    Exit;
  end;
    Hook[].UnHook;
    Result := TNewOpenProcess(Hook[].BaseAddr)(dwDesiredAccess, bInheritHandle, dwProcessId);
    Hook[].Hook;
end;

{--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--}

//安装API Hook
procedure InitHook;
begin
  Hook[] := TNtHookClass.Create('user32.dll', 'MessageBoxA', @NewMessageBoxA);
  Hook[] := TNtHookClass.Create('user32.dll', 'MessageBeep', @NewMessageBeep);
  Hook[] := TNtHookClass.Create('user32.dll', 'MessageBoxW', @NewMessageBoxW);
  Hook[] := TNtHookClass.Create('kernel32.dll', 'OpenProcess', @NewOpenProcess);
end;

//删除API Hook
procedure UninitHook;
var
  I: Integer;
begin
  for I :=  to High(Hook) do
  begin
    if Assigned(hook[I])then  //zl自己加的判断
      FreeAndNil(Hook[I]);
  end;
end;

{--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--}

//内存映射共享
procedure MemShared();
begin
  MemFile:=OpenFileMapping(FILE_MAP_ALL_ACCESS,False, HOOK_MEM_FILENAME);
//打开内存映射文件
if MemFile =  then
begin  //打开失败则衉c2建内存映射文件
    MemFile := CreateFileMapping($FFFFFFFF, nil, PAGE_READWRITE, ,
                              , HOOK_MEM_FILENAME);
end;
if MemFile <>  then
//映射文件到变量
    startPid := MapViewOfFile(MemFile,FILE_MAP_ALL_ACCESS,,,);
end;

//传递消息
function HookProc(nCode, wParam, lParam: Integer): Integer; stdcall;
begin
Result := CallNextHookEx(hhk, nCode, wParam, lParam);
end;

//开始HOOK
procedure StartHook(pid: DWORD); stdcall;
begin
  UninitHook;//zl自己加的

  startPid^ := pid;
  hhk := SetWindowsHookEx(WH_CALLWNDPROC, HookProc, hInstance, );

  InitHook;////zl自己加的
end;

//结束HOOK
procedure EndHook; stdcall;
begin
  if hhk <>  then
  begin
    UnhookWindowsHookEx(hhk);
    UninitHook;//zl自己加的
  end;
end;

//环境处理
procedure DllEntry(dwResaon: DWORD);
begin
case dwResaon of
    //DLL_PROCESS_ATTACH: InitHook;   //DLL载入  //zl自己屏蔽的
    DLL_PROCESS_DETACH: UninitHook; //DLL删除
end;
end;

exports
  StartHook, EndHook;

begin
  MemShared;

{ 分配DLL程序到 DllProc 变量 }
  DllProc := @DllEntry;
{ 调用DLL加载处理 }
  DllEntry(DLL_PROCESS_ATTACH);
end.

unit unitHook;

interface

uses
  Windows, Messages, Classes, SysUtils;

type

//NtHook类相关类型
  TNtJmpCode=packed record  //8字节
    MovEax:Byte;
    Addr:DWORD;
    JmpCode:Word;
    dwReserved:Byte;
end;

  TNtHookClass=class(TObject)
  private
      hProcess:THandle;
      NewAddr:TNtJmpCode;
      OldAddr:array[..] of Byte;
      ReadOK:Boolean;
  public
      BaseAddr:Pointer;
  constructor Create(DllName,FuncName:string;NewFunc:Pointer);
  destructor Destroy; override;
  procedure Hook;
  procedure UnHook;
end;

implementation

//==================================================
//NtHOOK 类开始
//==================================================
constructor TNtHookClass.Create(DllName: string; FuncName: string;NewFunc:Pointer);
var
  DllModule:HMODULE;
  dwReserved:DWORD;
begin
//获取模块句柄
  DllModule:=GetModuleHandle(PChar(DllName));
//如果得不到说明未被加载
if DllModule= then DllModule:=LoadLibrary(PChar(DllName));
//得到模块入口地址（基址）
  BaseAddr:=Pointer(GetProcAddress(DllModule,PChar(FuncName)));
//获取当前进程句柄
  hProcess:=GetCurrentProcess;
//指向新地址的指针
  NewAddr.MovEax:=$B8;
  NewAddr.Addr:=DWORD(NewFunc);
  NewAddr.JmpCode:=$E0FF;
//保存原始地址
  ReadOK:=ReadProcessMemory(hProcess,BaseAddr,@OldAddr,,dwReserved);
//开始拦截
  Hook;
end;

//释放对象
destructor TNtHookClass.Destroy;
begin
  UnHook;
CloseHandle(hProcess);

inherited;
end;

//开始拦截
procedure TNtHookClass.Hook;
var
  dwReserved:DWORD;
begin
if (ReadOK=False) then Exit;
//写入新的地址
WriteProcessMemory(hProcess,BaseAddr,@NewAddr,,dwReserved);
end;

//恢复拦截
procedure TNtHookClass.UnHook;
var
  dwReserved:DWORD;
begin
if (ReadOK=False) then Exit;
//恢复地址
WriteProcessMemory(hProcess,BaseAddr,@OldAddr,,dwReserved);
end;

end.

procedure StartHook(pid: DWORD); stdcall; external 'hookdll.dll';
procedure EndHook; stdcall; external 'hookdll.dll';

implementation

{$R *.dfm}

procedure TfrmMain.btnHookClick(Sender: TObject);
begin
  StartHook(GetCurrentProcessId);
end;

procedure TfrmMain.btnUnhookClick(Sender: TObject);
begin
  EndHook;
end;

procedure TfrmMain.Button1Click(Sender: TObject);
begin
  MessageBox(, '呵呵健健康康', nil, );
end;