截取程序的網絡封包（Delphi Hook API）

時間 2019-11-13

原文原文鏈接

有時候咱們須要對其它應用程序發送和接收的網絡數據進行攔截,好比要對IE發送的**頭進行分析,獲得請求的地址等.此次咱們能夠用一些例如WPE, Sniffer之類的工具來達到目的.可是工具功能有限,要想實現更強大的功能,仍是咱們本身動手來DIY吧.

攔截網絡數據封包的方法有三種,一是將網卡設爲混雜模式,此次就能夠監視到局域網上全部的數據包,二是HOOK目標進程的發送和接收的API函數,第三種方法是本身實現一個代理的DLL.在這裏咱們使用HOOK API的方法,這樣易於實現,並且也不會獲得大量的無用數據(如第一種方法就會監視到全部的網絡數據).

下面是一個儘可能簡化了的API HOOK的模版,原理是利用消息鉤子將DLL中的代碼注入到目標進程中,再用GetProcAddress獲得API函數入口地址,將函數入口址改成本身定義的函數入口,這樣就獲得了API函數的相應參數,處理完後,再改回真實API函數入口地址,並調用它.
HOOK.DLL的代碼:javascript

Delphi代碼 java

library Hook;
uses
SysUtils,
windows,
Messages,
APIHook in 'APIHook.pas';
type
PData = ^TData;
TData = record
Hook: THandle;
Hooked: Boolean;
end;
var
DLLData: PData;
{------------------------------------}
{過程名:HookProc
{過程功能:HOOK過程
{過程參數:nCode, wParam, lParam消息的相
{ 關參數
{------------------------------------}
procedure HookProc(nCode, wParam, lParam: LongWORD);stdcall;
begin
if not DLLData^.Hooked then
begin
HookAPI;
DLLData^.Hooked := True;
end;
//調用下一個Hook
CallNextHookEx(DLLData^.Hook, nCode, wParam, lParam);
end;
{------------------------------------}
{函數名:InstallHook
{函數功能:在指定窗口上安裝HOOK
{函數參數:sWindow:要安裝HOOK的窗口
{返回值:成功返回TRUE,失敗返回FALSE
{------------------------------------}
function InstallHook(SWindow: LongWORD):Boolean;stdcall;
var
ThreadID: LongWORD;
begin
Result := False;
DLLData^.Hook := 0;
ThreadID := GetWindowThreadProcessId(sWindow, nil);
//給指定窗口掛上鉤子
DLLData^.Hook := SetWindowsHookEx(WH_GETMESSAGE, @HookProc, Hinstance, ThreadID);
if DLLData^.Hook > 0 then
Result := True //是否成功HOOK
else
exit;
end;
{------------------------------------}
{過程名:UnHook
{過程功能:卸載HOOK
{過程參數:無
{------------------------------------}
procedure UnHook;stdcall;
begin
UnHookAPI;
//卸載Hook
UnhookWindowsHookEx(DLLData^.Hook);
end;
{------------------------------------}
{過程名:DLL入口函數
{過程功能:進行DLL初始化,釋放等
{過程參數:DLL狀態
{------------------------------------}
procedure MyDLLHandler(Reason: Integer);
var
FHandle: LongWORD;
begin
case Reason of
DLL_PROCESS_ATTACH:
begin //創建文件映射,以實現DLL中的全局變量
FHandle := CreateFileMapping($FFFFFFFF, nil, PAGE_READWRITE, 0, $ffff, 'MYDLLDATA');
if FHandle = 0 then
if GetLastError = ERROR_ALREADY_EXISTS then
begin
FHandle := OpenFileMapping(FILE_MAP_ALL_ACCESS, False, 'MYDLLDATA');
if FHandle = 0 then Exit;
end else Exit;
DLLData := MapViewOfFile(FHandle, FILE_MAP_ALL_ACCESS, 0, 0, 0);
if DLLData = nil then
CloseHandle(FHandle);
end;
DLL_PROCESS_DETACH:
begin
if Assigned(DLLData) then
begin
UnmapViewOfFile(DLLData);
DLLData := nil;
end;
end;
end;
end;
{$R *.res}
exports
InstallHook, UnHook, HookProc;
begin
DLLProc := @MyDLLHandler;
MyDLLhandler(DLL_PROCESS_ATTACH);
DLLData^.Hooked := False;
end.
----------------------------------------------------------------------------------------
APIHook.Pas的代碼:
unit APIHook;
interface
uses
SysUtils,
Windows, WinSock;
type
//要HOOK的API函數定義
TSockProc = function (s: TSocket; var Buf; len, flags: Integer): Integer; stdcall;
PJmpCode = ^TJmpCode;
TJmpCode = packed record
JmpCode: BYTE;
Address: TSockProc;
MovEAX: Array [0..2] of BYTE;
end;
//--------------------函數聲明---------------------------
procedure HookAPI;
procedure UnHookAPI;
var
OldSend, OldRecv: TSockProc; //原來的API地址
JmpCode: TJmpCode;
OldProc: array [0..1] of TJmpCode;
AddSend, AddRecv: pointer; //API地址
TmpJmp: TJmpCode;
ProcessHandle: THandle;
implementation
{---------------------------------------}
{函數功能:Send函數的HOOK
{函數參數:同Send
{函數返回值:integer
{---------------------------------------}
function MySend(s: TSocket; var Buf; len, flags: Integer): Integer; stdcall;
var
dwSize: cardinal;
begin
//這兒進行發送的數據處理
MessageBeep(1000); //簡單的響一聲
//調用直正的Send函數
WriteProcessMemory(ProcessHandle, AddSend, @OldProc[0], 8, dwSize);
Result := OldSend(S, Buf, len, flags);
JmpCode.Address := @MySend;
WriteProcessMemory(ProcessHandle, AddSend, @JmpCode, 8, dwSize);
end;
{---------------------------------------}
{函數功能:Recv函數的HOOK
{函數參數:同Recv
{函數返回值:integer
{---------------------------------------}
function MyRecv(s: TSocket; var Buf; len, flags: Integer): Integer; stdcall;
var
dwSize: cardinal;
begin
//這兒進行接收的數據處理
MessageBeep(1000); //簡單的響一聲
//調用直正的Recv函數
WriteProcessMemory(ProcessHandle, AddRecv, @OldProc[1], 8, dwSize);
Result := OldRecv(S, Buf, len, flags);
JmpCode.Address := @MyRecv;
WriteProcessMemory(ProcessHandle, AddRecv, @JmpCode, 8, dwSize);
end;
{------------------------------------}
{過程功能:HookAPI
{過程參數:無
{------------------------------------}
procedure HookAPI;
var
DLLModule: THandle;
dwSize: cardinal;
begin
ProcessHandle := GetCurrentProcess;
DLLModule := LoadLibrary('ws2_32.dll');
AddSend := GetProcAddress(DLLModule, 'send'); //取得API地址
AddRecv := GetProcAddress(DLLModule, 'recv');
JmpCode.JmpCode := $B8;
JmpCode.MovEAX[0] := $FF;
JmpCode.MovEAX[1] := $E0;
JmpCode.MovEAX[2] := 0;
ReadProcessMemory(ProcessHandle, AddSend, @OldProc[0], 8, dwSize);
JmpCode.Address := @MySend;
WriteProcessMemory(ProcessHandle, AddSend, @JmpCode, 8, dwSize); //修改Send入口
ReadProcessMemory(ProcessHandle, AddRecv, @OldProc[1], 8, dwSize);
JmpCode.Address := @MyRecv;
WriteProcessMemory(ProcessHandle, AddRecv, @JmpCode, 8, dwSize); //修改Recv入口
OldSend := AddSend;
OldRecv := AddRecv;
end;
{------------------------------------}
{過程功能:取消HOOKAPI
{過程參數:無
{------------------------------------}
procedure UnHookAPI;
var
dwSize: Cardinal;
begin
WriteProcessMemory(ProcessHandle, AddSend, @OldProc[0], 8, dwSize);
WriteProcessMemory(ProcessHandle, AddRecv, @OldProc[1], 8, dwSize);
end;
end.

---------------------------------------------------------------------------------------------
編譯這個DLL後,再新建一個程序調用這個DLL的InstallHook並傳入目標進程的主窗口句柄就可:windows

Delphi代碼網絡