最近、明らかに正当なソースから取引アプリケーションをインストールしました。リモートサーバーに接続され、管理者モードで実行されます。私たちの知らないうちに悪意のある活動をした場合、私は負傷します。画面の内容を記録し、リモートサーバーに送信する。
キーロガーなどのように、画面印刷コマンドがトリガーされたかどうかを検出することはできますか?または、プログラムが私たちをスパイしているかどうかを確認する他の方法はありますか?
さらに調査した後、StackOverflowで答えを見つけ、グローバルインターセプターを作成しました。
リファレンス: https://stackoverflow.com/questions/604410/global-keyboard-capture-in-c-sharp-application
C#VS2005用の私の作業コードは次のとおりです。
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.InteropServices;
namespace Interceptor
{
class GlobalKeyboardHookEventArgs : HandledEventArgs
{
private GlobalKeyboardHook.KeyboardState keyboardState;
private GlobalKeyboardHook.LowLevelKeyboardInputEvent keyboardData;
public GlobalKeyboardHook.KeyboardState KeyboardState
{
get { return keyboardState; }
set { this.keyboardState = value; }
}
public GlobalKeyboardHook.LowLevelKeyboardInputEvent KeyboardData {
get { return keyboardData; }
set { this.keyboardData = value; }
}
public GlobalKeyboardHookEventArgs(
GlobalKeyboardHook.LowLevelKeyboardInputEvent keyboardData,
GlobalKeyboardHook.KeyboardState keyboardState)
{
KeyboardData = keyboardData;
KeyboardState = keyboardState;
}
}
//Based on https://Gist.github.com/Stasonix
class GlobalKeyboardHook : IDisposable
{
public event EventHandler<GlobalKeyboardHookEventArgs> KeyboardPressed;
public GlobalKeyboardHook()
{
_windowsHookHandle = IntPtr.Zero;
_user32LibraryHandle = IntPtr.Zero;
_hookProc = LowLevelKeyboardProc; // we must keep alive _hookProc, because GC is not aware about SetWindowsHookEx behaviour.
_user32LibraryHandle = LoadLibrary("User32");
if (_user32LibraryHandle == IntPtr.Zero)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, "Failed to load library 'User32.dll'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_windowsHookHandle = SetWindowsHookEx(WH_KEYBOARD_LL, _hookProc, _user32LibraryHandle, 0);
if (_windowsHookHandle == IntPtr.Zero)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, "Failed to adjust keyboard hooks for '{Process.GetCurrentProcess().ProcessName}'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
// because we can unhook only in the same thread, not in garbage collector thread
if (_windowsHookHandle != IntPtr.Zero)
{
if (!UnhookWindowsHookEx(_windowsHookHandle))
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, "Failed to remove keyboard hooks for '{Process.GetCurrentProcess().ProcessName}'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_windowsHookHandle = IntPtr.Zero;
// ReSharper disable once DelegateSubtraction
_hookProc -= LowLevelKeyboardProc;
}
}
if (_user32LibraryHandle != IntPtr.Zero)
{
if (!FreeLibrary(_user32LibraryHandle)) // reduces reference to library by 1.
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, "Failed to unload library 'User32.dll'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_user32LibraryHandle = IntPtr.Zero;
}
}
~GlobalKeyboardHook()
{
Dispose(false);
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
private IntPtr _windowsHookHandle;
private IntPtr _user32LibraryHandle;
private HookProc _hookProc;
delegate IntPtr HookProc(int nCode, IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll")]
private static extern IntPtr LoadLibrary(string lpFileName);
[DllImport("kernel32.dll", CharSet = CharSet.Auto)]
private static extern bool FreeLibrary(IntPtr hModule);
/// <summary>
/// The SetWindowsHookEx function installs an application-defined hook procedure into a hook chain.
/// You would install a hook procedure to monitor the system for certain types of events. These events are
/// associated either with a specific thread or with all threads in the same desktop as the calling thread.
/// </summary>
/// <param name="idHook">hook type</param>
/// <param name="lpfn">hook procedure</param>
/// <param name="hMod">handle to application instance</param>
/// <param name="dwThreadId">thread identifier</param>
/// <returns>If the function succeeds, the return value is the handle to the hook procedure.</returns>
[DllImport("USER32", SetLastError = true)]
static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hMod, int dwThreadId);
/// <summary>
/// The UnhookWindowsHookEx function removes a hook procedure installed in a hook chain by the SetWindowsHookEx function.
/// </summary>
/// <param name="hhk">handle to hook procedure</param>
/// <returns>If the function succeeds, the return value is true.</returns>
[DllImport("USER32", SetLastError = true)]
public static extern bool UnhookWindowsHookEx(IntPtr hHook);
/// <summary>
/// The CallNextHookEx function passes the hook information to the next hook procedure in the current hook chain.
/// A hook procedure can call this function either before or after processing the hook information.
/// </summary>
/// <param name="hHook">handle to current hook</param>
/// <param name="code">hook code passed to hook procedure</param>
/// <param name="wParam">value passed to hook procedure</param>
/// <param name="lParam">value passed to hook procedure</param>
/// <returns>If the function succeeds, the return value is true.</returns>
[DllImport("USER32", SetLastError = true)]
static extern IntPtr CallNextHookEx(IntPtr hHook, int code, IntPtr wParam, IntPtr lParam);
[StructLayout(LayoutKind.Sequential)]
public struct LowLevelKeyboardInputEvent
{
/// <summary>
/// A virtual-key code. The code must be a value in the range 1 to 254.
/// </summary>
public int VirtualCode;
/// <summary>
/// A hardware scan code for the key.
/// </summary>
public int HardwareScanCode;
/// <summary>
/// The extended-key flag, event-injected Flags, context code, and transition-state flag. This member is specified as follows. An application can use the following values to test the keystroke Flags. Testing LLKHF_INJECTED (bit 4) will tell you whether the event was injected. If it was, then testing LLKHF_LOWER_IL_INJECTED (bit 1) will tell you whether or not the event was injected from a process running at lower integrity level.
/// </summary>
public int Flags;
/// <summary>
/// The time stamp stamp for this message, equivalent to what GetMessageTime would return for this message.
/// </summary>
public int TimeStamp;
/// <summary>
/// Additional information associated with the message.
/// </summary>
public IntPtr AdditionalInformation;
}
public const int WH_KEYBOARD_LL = 13;
//const int HC_ACTION = 0;
public enum KeyboardState
{
KeyDown = 0x0100,
KeyUp = 0x0101,
SysKeyDown = 0x0104,
SysKeyUp = 0x0105
}
public const int VkSnapshot = 0x2c;
//const int VkLwin = 0x5b;
//const int VkRwin = 0x5c;
//const int VkTab = 0x09;
//const int VkEscape = 0x18;
//const int VkControl = 0x11;
const int KfAltdown = 0x2000;
public const int LlkhfAltdown = (KfAltdown >> 8);
public IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam)
{
bool fEatKeyStroke = false;
int wparamTyped = wParam.ToInt32();
if (Enum.IsDefined(typeof(KeyboardState), wparamTyped))
{
object o = Marshal.PtrToStructure(lParam, typeof(LowLevelKeyboardInputEvent));
LowLevelKeyboardInputEvent p = (LowLevelKeyboardInputEvent)o;
GlobalKeyboardHookEventArgs eventArguments = new GlobalKeyboardHookEventArgs(p, (KeyboardState)wparamTyped);
EventHandler<GlobalKeyboardHookEventArgs> handler = KeyboardPressed;
handler.Invoke(this, eventArguments);
fEatKeyStroke = eventArguments.Handled;
}
return fEatKeyStroke ? (IntPtr)1 : CallNextHookEx(IntPtr.Zero, nCode, wParam, lParam);
}
}
}
使用法:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace Interceptor
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
SetupKeyboardHooks();
}
private GlobalKeyboardHook _globalKeyboardHook;
public void SetupKeyboardHooks()
{
_globalKeyboardHook = new GlobalKeyboardHook();
_globalKeyboardHook.KeyboardPressed += OnKeyPressed;
}
private void OnKeyPressed(object sender, GlobalKeyboardHookEventArgs e)
{
//Debug.WriteLine(e.KeyboardData.VirtualCode);
if (e.KeyboardData.VirtualCode != GlobalKeyboardHook.VkSnapshot)
return;
// seems, not needed in the life.
//if (e.KeyboardState == GlobalKeyboardHook.KeyboardState.SysKeyDown &&
// e.KeyboardData.Flags == GlobalKeyboardHook.LlkhfAltdown)
//{
// MessageBox.Show("Alt + Print Screen");
// e.Handled = true;
//}
//else
if (e.KeyboardState == GlobalKeyboardHook.KeyboardState.KeyDown)
{
MessageBox.Show("Print Screen");
e.Handled = true;
}
}
public void Dispose()
{
_globalKeyboardHook.Dispose();
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
this.Dispose();
}
}
}
アプリがあなたをスパイしているかどうかを判断するための3つの実行可能なパスがわかります。
これらの方法はどれも完全にフェイルセーフではありません。プログラムを販売している人々を信用できないと思われる場合は、プログラムをまったく実行してはいけないと言ったくなります。
知らないアウトバウンドトラフィックが検出された場合、 通知するようにWindowsファイアウォールを設定 できます。
警告:Windowsでは、見慣れない多くの通常の送信トラフィックが作成される可能性があるため、ブロックする内容に注意してください。