运行分析

• 需要破解Hard Coded和Name+Serial

---

PE分析

• ASM程序，32位，无壳

---

静态分析&动态调试

Hard Coded

• ida发现关键字符串，进入Hard Code函数

---

LRESULT __stdcall sub_401178(HWND hWndParent, UINT Msg, WPARAM wParam, LPARAM lParam)
{
  const char *v4; // eax
  CHAR *i; // ebx

  switch ( Msg )
  {
    case 2u:
      PostQuitMessage(0);
      break;
    case 1u:
      CreateWindowExA(0, aStatic, aHardCoded, 0x50000080u, 10, 2, 100, 25, hWndParent, (HMENU)6, hInstance, 0);
      CreateWindowExA(0, aStatic, aName, 0x50000080u, 10, 65, 100, 25, hWndParent, (HMENU)7, hInstance, 0);
      CreateWindowExA(0, aStatic, aSerial, 0x50000080u, 10, 105, 100, 25, hWndParent, (HMENU)7, hInstance, 0);
      hWnd = CreateWindowExA(0x200u, aEdit, 0, 0x50800080u, 101, 0, 175, 25, hWndParent, (HMENU)3, hInstance, 0);
      dword_403494 = CreateWindowExA(
                       0x200u,
                       aEdit,
                       0,
                       0x50800080u,
                       101,
                       60,
                       175,
                       25,
                       hWndParent,
                       (HMENU)4,
                       hInstance,
                       0);
      dword_403498 = CreateWindowExA(
                       0x200u,
                       aEdit,
                       0,
                       0x50800080u,
                       101,
                       100,
                       175,
                       25,
                       hWndParent,
                       (HMENU)5,
                       hInstance,
                       0);
      SetFocus(hWnd);
      dword_403488 = (int)CreateWindowExA(
                            0,
                            aButton,
                            aCheckHardcoded,
                            0x50000001u,
                            75,
                            30,
                            140,
                            25,
                            hWndParent,
                            (HMENU)1,
                            hInstance,
                            0);
      dword_40348C = (int)CreateWindowExA(
                            0,
                            aButton,
                            aNameSerialChec,
                            0x50000001u,
                            75,
                            130,
                            140,
                            25,
                            hWndParent,
                            (HMENU)2,
                            hInstance,
                            0);
      break;
    case 0x111u:
      if ( (_WORD)wParam == 1 )                 // 第一个按钮
      {
        if ( !HIWORD(wParam) )
        {
          GetWindowTextA(hWnd, String, 32);     // 获得Hard Code
          v4 = "HardCoded";
          for ( i = String; ; ++i )
          {
            if ( !*v4 )
            {
              MessageBoxA(0, "Congratulations, you got the hard coded serial", Caption, 0);
              return 0;
            }
            if ( *v4 != *i )                    // Hard Code = "HardCoded"
              break;
            ++v4;
          }
          MessageBoxA(0, aSorryPleaseTry, Caption, 0);
        }
      }
      else if ( (_WORD)wParam == 2 )            // 第二个按钮
      {
        if ( !HIWORD(wParam) )
          sub_4015E4(dword_403494, dword_403498);// Name和Serial函数
      }
      else if ( wParam == 1000 )
      {
        SendMessageA(hWndParent, 0x112u, 0xF060u, 0);
      }
      else if ( wParam == 1100 )
      {
        MessageBoxA(0, aYourMissionIsT, Caption, 0);
      }
      break;
    default:
      return DefWindowProcA(hWndParent, Msg, wParam, lParam);
  }
  return 0;
}

• Hard Coded明文出现了，为HardCoded

---

---

Name & Serial

• 通过sub_4015E4(dword_403494, dword_403498);进入Name和Serial判断函数

---

int __stdcall sub_4015E4(HWND a1, HWND hWnd)
{
  int WindowTextA; // eax
  int v3; // eax
  int v4; // ebx
  int v5; // edx
  int v6; // ebx
  int i; // ebx

  WindowTextA = GetWindowTextA(hWnd, Serial, 32);
  if ( !WindowTextA )
    return MessageBoxA(0, aPleaseEnterYou_0, Caption, 0);// 弹窗'Please enter your serial number.'
  dword_403467 = WindowTextA;
  v3 = GetWindowTextA(a1, Name, 11);            // Name最大取11位
  if ( !v3 )
    return MessageBoxA(0, aPleaseEnterYou, Caption, 0);// 弹窗'Please enter your name.'
  Name_length = v3;
  v4 = 0;
  do
  {
    v5 = (v4 ^ (Name[v4] % 10)) + 2;
    if ( (char)v5 >= 10 )
      LOBYTE(v5) = (v4 ^ (Name[v4] % 10)) - 8;
    res_Name[v4++] = v5;
  }
  while ( v4 != Name_length );                  // 通过上述计算得到res_Name
  v6 = 0;
  do
  {
    res_Serial[v6] = Serial[v6] % 10;
    ++v6;
  }
  while ( v6 != dword_403467 );                 // 通过上述计算得到res_Serial
  for ( i = 0; ; ++i )
  {
    if ( i == Name_length )
      return MessageBoxA(0, aGoodJobNowKeyg, Caption, 0);// 弹窗'Good job, now keygen it.'
    if ( res_Name[i] != res_Serial[i] )         // 若res_Name == res_Serial，则弹出上面弹窗
      break;
  }
  return MessageBoxA(0, aSorryPleaseTry, Caption, 0);// 弹窗'Sorry, please try again.'
}

• 通过一系列计算得到res_Name和res_Serial
• 若res_Name == res_Serial，则弹窗破解成功

---

算法分析

Name = 'concealbear'
Serial = ''
res_Name = []
res_Serial = []

# 通过Name计算res_Name
for v4 in range(len(Name)):
    v5 = (v4 ^ (ord(Name[v4]) % 10)) + 2
    if (v5 >= 10):
        v5 = (v4 ^ (ord(Name[v4]) % 10)) - 8
    res_Name.append(v5)

# 逆向计算Serial
res_Serial = res_Name
for i in range(len(res_Serial)):
    res_Serial[i] = res_Serial[i] + 100         # 因为是求余，res_Serial都是各位数字，ascii码值中个位数字+100都是小写字母
    Serial += chr(res_Serial[i])

print(Name + '的Serial为：\n' + Serial)

• 通过算法，输入任意Name得到Serial，验证成功