系统 ： Windows xp
程序 ： Crackme#3 - Self Destructed
程序下载地址 ：http://pan.baidu.com/s/1kVxwlaZ
要求 ： 注册机编写
使用工具 ： OD
可在“PEDIY CrackMe 2007”中查找关于此程序的讨论，标题为“适合新手的D4ph1_-_Crackme#3的破解”。
利用超级字符串插件看下程序内的文本：
Ultra String Reference
Address Disassembly Text String
00401000 mov esi, dword ptr [esp] (initial cpu selection)
00401068 push 0040313A kernel32.dll
00401229 push 00403147 eraser.bat
00401255 push 00403147 eraser.bat
0040125C push 00403153 :loop
del "%s"
if exist "%s" goto loop
del "%s"
00401289 push 00403000 crackme#3 by d4ph1
0040128E push 00403186 debugger found...i think im gonna kill myself!:(
004012A0 push 00403147 eraser.bat
00401346 push 00403000 crackme#3 by d4ph1
0040134B push 00403013 *======== your target is to create a valid keygenerator.contact : fistiks16@hotmail.com ========*
004014AB push 00403000 crackme#3 by d4ph1
004014B0 push 004030E0 great work!hope this is coming from your keygenerator!:)
004014C0 push 00403000 crackme#3 by d4ph1
004014C5 push 00403119 this is not the right serial...
004014D5 push 00403000 crackme#3 by d4ph1
004014DA push 004030BB you have to write a serial first...!
004014F3 push 00403000 crackme#3 by d4ph1
004014F8 push 00403098 you have to write a name first...!
00401508 push 00403000 crackme#3 by d4ph1
0040150D push 00403075 the name you write is not correct!
好像检索出了什么不得了的内容，双击debugger found...i think im gonna kill myself!:( 查看引用位置：
004011F3 /$ 68 D1314000 push 004031D1 ; /isdebuggerpresent
004011F8 |. FF35 F0344000 push dword ptr [4034F0] ; |hModule = NULL
004011FE |. E8 8B030000 call <jmp.&kernel32.GetProcAddress> ; GetProcAddress
00401203 |. FFD0 call eax
00401205 |. 0BC0 or eax, eax
00401207 |. 75 0C jnz short 00401215
00401209 |. 8A1D 07124000 mov bl, byte ptr [401207]
0040120F |. 80FB 75 cmp bl, 75
00401212 |. 75 03 jnz short 00401217
00401214 |. C3 retn
00401215 |> EB 00 jmp short 00401217
00401217 |> 6A 00 push 0 ; /hTemplateFile = NULL
00401219 |. 68 80000000 push 80 ; |Attributes = NORMAL
0040121E |. 6A 02 push 2 ; |Mode = CREATE_ALWAYS
00401220 |. 6A 00 push 0 ; |pSecurity = NULL
00401222 |. 6A 00 push 0 ; |ShareMode = 0
00401224 |. 68 00000040 push 40000000 ; |Access = GENERIC_WRITE
00401229 |. 68 47314000 push 00403147 ; |eraser.bat
0040122E |. E8 37030000 call <jmp.&kernel32.CreateFileA> ; CreateFileA
00401233 |. 8BD8 mov ebx, eax
00401235 |. 8D35 0A394000 lea esi, dword ptr [40390A]
0040123B |. 68 04010000 push 104 ; /BufSize = 104 (260.)
00401240 |. 56 push esi ; |PathBuffer => Crackme#.0040390A
00401241 |. 6A 00 push 0 ; |hModule = NULL
00401243 |. E8 3A030000 call <jmp.&kernel32.GetModuleFileName>; GetModuleFileNameA
00401248 |. 56 push esi ; /pDest => Crackme#.0040390A
00401249 |. 56 push esi ; |pSrc => ""
0040124A |. E8 E5020000 call <jmp.&user32.CharToOemA> ; CharToOemA
0040124F |. 8D3D 0A354000 lea edi, dword ptr [40350A]
00401255 |. 68 47314000 push 00403147 ; /eraser.bat
0040125A |. 56 push esi ; |<%s> => ""
0040125B |. 56 push esi ; |<%s> => ""
0040125C |. 68 53314000 push 00403153 ; |:loop
del "%s"
if exist "%s" goto loop
del "%s"
00401261 |. 57 push edi ; |s => Crackme#.0040350A
00401262 |. E8 C7020000 call <jmp.&user32.wsprintfA> ; wsprintfA
00401267 |. 83C4 14 add esp, 14
0040126A |. 57 push edi ; /String
0040126B |. E8 3C030000 call <jmp.&kernel32.lstrlenA> ; lstrlenA
00401270 |. 8D15 0E3A4000 lea edx, dword ptr [403A0E]
00401276 |. 6A 00 push 0 ; /pOverlapped = NULL
00401278 |. 52 push edx ; |pBytesWritten => Crackme#.00403A0E
00401279 |. 50 push eax ; |nBytesToWrite
0040127A |. 57 push edi ; |Buffer
0040127B |. 53 push ebx ; |hFile
0040127C |. E8 25030000 call <jmp.&kernel32.WriteFile> ; WriteFile
00401281 |. 53 push ebx ; /hObject
00401282 |. E8 DD020000 call <jmp.&kernel32.CloseHandle> ; CloseHandle
00401287 |. 6A 10 push 10 ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
00401289 |. 68 00304000 push 00403000 ; |crackme#3 by d4ph1
0040128E |. 68 86314000 push 00403186 ; |debugger found...i think im gonna kill myself!:(
00401293 |. 6A 00 push 0 ; |hOwner = NULL
00401295 |. E8 B2020000 call <jmp.&user32.MessageBoxA> ; MessageBoxA
0040129A |. 6A 00 push 0 ; /IsShown = 0
0040129C |. 6A 00 push 0 ; |DefDir = NULL
0040129E |. 6A 00 push 0 ; |Parameters = NULL
004012A0 |. 68 47314000 push 00403147 ; |eraser.bat
004012A5 |. 6A 00 push 0 ; |Operation = NULL
004012A7 |. 6A 00 push 0 ; |hWnd = NULL
004012A9 |. E8 04030000 call <jmp.&shell32.ShellExecuteA> ; ShellExecuteA
004012AE |. 6A 00 push 0 ; /ExitCode = 0
004012B0 . E8 BB020000 call <jmp.&kernel32.ExitProcess> ; ExitProcess
程序启动时利用WINAPI 查看是否被调试，如果被调试则创建批处理文件：
:LOOP
DEL "D:IT逆向工程CrackMecrackme3selfdestructedCrackme#3 - Self Destructed.exe"
IF EXIST "D:IT逆向工程CrackMecrackme3selfdestructedCrackme#3 - Self Destructed.exe" GOTO LOOP
DEL "ERASER.BAT"
启动批处理开始循环删除之后，退出程序。批处理删除源程序之后，再删除自身。很有想法的一个反调试机制。
再来看看算法部分：
00401366 |. 68 EC314000 push 004031EC ; /123
0040136B |. 68 80000000 push 80 ; |wParam = 80
00401370 |. 6A 0D push 0D ; |Message = WM_GETTEXT
00401372 |. 68 EA030000 push 3EA ; |ControlID = 3EA (1002.)
00401377 |. FF75 08 push dword ptr [ebp+8] ; |hWnd
0040137A |. E8 D9010000 call <jmp.&user32.SendDlgItemMessageA>; SendDlgItemMessageA
0040137F |. A3 6C324000 mov dword ptr [40326C], eax
00401384 |. 83F8 04 cmp eax, 4 ; 长度低于等于4？
00401387 |. 0F86 60010000 jbe 004014ED ; 是则报错
0040138D |. 83F8 14 cmp eax, 14 ; 长度高于等于14？
00401390 |. 0F83 57010000 jnb 004014ED ; 是则报错
00401396 |. 68 70324000 push 00403270 ; /lParam = 403270
0040139B |. 68 00010000 push 100 ; |wParam = 100
004013A0 |. 6A 0D push 0D ; |Message = WM_GETTEXT
004013A2 |. 68 EB030000 push 3EB ; |ControlID = 3EB (1003.)
004013A7 |. FF75 08 push dword ptr [ebp+8] ; |hWnd
004013AA |. E8 A9010000 call <jmp.&user32.SendDlgItemMessageA>; SendDlgItemMessageA
004013AF |. 83F8 00 cmp eax, 0 ; 长度为0则报错
004013B2 |. 0F84 1B010000 je 004014D3
004013B8 |. 33C9 xor ecx, ecx ; 开始初始化
004013BA |. 49 dec ecx
004013BB |. 33D2 xor edx, edx
004013BD |. 4A dec edx
004013BE |. 33F6 xor esi, esi
004013C0 |. 4E dec esi
004013C1 |. 33C0 xor eax, eax
004013C3 |. A1 6C324000 mov eax, dword ptr [40326C] ; 载入用户名长度
004013C8 |. 48 dec eax
004013C9 |. 50 push eax
004013CA |> 46 /inc esi
004013CB |. 41 |inc ecx
004013CC |. 0FBE81 F03440>|movsx eax, byte ptr [ecx+4034F0] ; 遍历一个特定字符串
004013D3 |. 0FBE9E EC3140>|movsx ebx, byte ptr [esi+4031EC] ; 遍历用户名字符串
004013DA |. 83F0 12 |xor eax, 12
004013DD |. 83C0 34 |add eax, 34
004013E0 |. C1E3 03 |shl ebx, 3
004013E3 |. 83EB 20 |sub ebx, 20
004013E6 |. 83F3 66 |xor ebx, 66
004013E9 |. 32C3 |xor al, bl
004013EB |. 03C3 |add eax, ebx
004013ED |. E8 5CFDFFFF |call 0040114E ; 根据eax的值算出一个对应的值，并保存
004013F2 |. 58 |pop eax
004013F3 |. 3BF0 |cmp esi, eax ; 是否已经遍历结束？
004013F5 |. 50 |push eax
004013F6 |. 74 0A |je short 00401402
004013F8 |. 83F9 03 |cmp ecx, 3 ; 第4次循环的时候，重置ecx为-1
004013FB |. 75 03 |jnz short 00401400
004013FD |. 33C9 |xor ecx, ecx
004013FF |. 49 |dec ecx
00401400 |>^ EB C8 jmp short 004013CA
00401402 |> 58 pop eax
00401403 |. 42 inc edx
00401404 |. C682 70334000>mov byte ptr [edx+403370], 2D ; 添加连字符-
0040140B |. 33C9 xor ecx, ecx
0040140D |. 49 dec ecx
0040140E |. BB 13000000 mov ebx, 13
00401413 |. 33C0 xor eax, eax
00401415 |> 41 /inc ecx
00401416 |. 0FBEB1 F43440>|movsx esi, byte ptr [ecx+4034F4] ; 遍历一个特定字符串
0040141D |. 0FBEBB B73140>|movsx edi, byte ptr [ebx+4031B7] ; 遍历一个特定字符串
00401424 |. 2BFE |sub edi, esi
00401426 |. 03C7 |add eax, edi
00401428 |. 2BC6 |sub eax, esi
0040142A |. C1E0 04 |shl eax, 4
0040142D |. 83F9 01 |cmp ecx, 1 ; 循环两次了？
00401430 |.^ 75 E3 jnz short 00401415
00401432 |. C1E8 04 shr eax, 4
00401435 |. 33C9 xor ecx, ecx
00401437 |. 49 dec ecx
00401438 |> 41 /inc ecx
00401439 |. E8 10FDFFFF |call 0040114E ; 根据eax的值算出一个对应的值，并保存
0040143E |. 8AC4 |mov al, ah
00401440 |. 83F9 01 |cmp ecx, 1 ; 循环两次了？
00401443 |.^ 75 F3 jnz short 00401438
00401445 |. 42 inc edx
00401446 |. C682 70334000>mov byte ptr [edx+403370], 2D ; 添加连字符-
0040144D |. 33C9 xor ecx, ecx
0040144F |. 49 dec ecx
00401450 |. 33FF xor edi, edi
00401452 |. 0FBE35 063540>movsx esi, byte ptr [403506]
00401459 |> 41 /inc ecx
0040145A |. 0FBE81 F63440>|movsx eax, byte ptr [ecx+4034F6] ; 遍历一个特定字符串
00401461 |. 8B9F 07124000 |mov ebx, dword ptr [edi+401207] ; 遍历一个代码区段
00401467 |. 33C3 |xor eax, ebx
00401469 |. 331D 06354000 |xor ebx, dword ptr [403506]
0040146F |. 2BD8 |sub ebx, eax
00401471 |. 2B1D 06354000 |sub ebx, dword ptr [403506]
00401477 |. 03C3 |add eax, ebx
00401479 |. E8 D0FCFFFF |call 0040114E ; 根据eax的值算出一个对应的值，并保存
0040147E |. 83C7 04 |add edi, 4
00401481 |. 4E |dec esi ; 循环结束？
00401482 |.^ 75 D5 jnz short 00401459
00401484 |. 68 70334000 push 00403370 ; /String = ""
00401489 |. E8 1E010000 call <jmp.&kernel32.lstrlenA> ; lstrlenA
0040148E |. 8BC8 mov ecx, eax
00401490 |. 41 inc ecx
00401491 |> 49 /dec ecx ; 密码和序列号是否一致？
00401492 |. 0FBE81 703240>|movsx eax, byte ptr [ecx+403270]
00401499 |. 0FBE99 703340>|movsx ebx, byte ptr [ecx+403370]
004014A0 |. 3BC3 |cmp eax, ebx
004014A2 |. 75 1A |jnz short 004014BE
004014A4 |. 83F9 00 |cmp ecx, 0
004014A7 |.^ 75 E8 jnz short 00401491
004014A9 |. 6A 00 push 0 ; /Style = MB_OK|MB_APPLMODAL
004014AB |. 68 00304000 push 00403000 ; |crackme#3 by d4ph1
004014B0 |. 68 E0304000 push 004030E0 ; |great work!hope this is coming from your keygenerator!:)
004014B5 |. 6A 00 push 0 ; |hOwner = NULL
004014B7 |. E8 90000000 call <jmp.&user32.MessageBoxA> ; MessageBoxA
004014BC |. EB 28 jmp short 004014E6
004014BE |> 6A 10 push 10 ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
004014C0 |. 68 00304000 push 00403000 ; |crackme#3 by d4ph1
004014C5 |. 68 19314000 push 00403119 ; |this is not the right serial...
004014CA |. 6A 00 push 0 ; |hOwner = NULL
004014CC |. E8 7B000000 call <jmp.&user32.MessageBoxA> ; MessageBoxA
004014D1 |. EB 13 jmp short 004014E6
004014D3 |> 6A 10 push 10 ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
004014D5 |. 68 00304000 push 00403000 ; |crackme#3 by d4ph1
004014DA |. 68 BB304000 push 004030BB ; |you have to write a serial first...!
004014DF |. 6A 00 push 0 ; |hOwner = NULL
004014E1 |. E8 66000000 call <jmp.&user32.MessageBoxA> ; MessageBoxA
004014E6 |> E8 93FCFFFF call 0040117E
004014EB |. EB 2C jmp short 00401519
004014ED |> 0BC0 or eax, eax
004014EF |. 75 15 jnz short 00401506
004014F1 |. 6A 10 push 10 ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
004014F3 |. 68 00304000 push 00403000 ; |crackme#3 by d4ph1
004014F8 |. 68 98304000 push 00403098 ; |you have to write a name first...!
004014FD |. 6A 00 push 0 ; |hOwner = NULL
004014FF |. E8 48000000 call <jmp.&user32.MessageBoxA> ; MessageBoxA
00401504 |. EB 13 jmp short 00401519
00401506 |> 6A 10 push 10 ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
00401508 |. 68 00304000 push 00403000 ; |crackme#3 by d4ph1
0040150D |. 68 75304000 push 00403075 ; |the name you write is not correct!
00401512 |. 6A 00 push 0 ; |hOwner = NULL
00401514 |. E8 33000000 call <jmp.&user32.MessageBoxA> ; MessageBoxA
00401519 |> EB 09 jmp short 00401524
0040151B |> B8 00000000 mov eax, 0
00401520 |. C9 leave
00401521 |. C2 1000 retn 10
00401524 |> B8 01000000 mov eax, 1
00401529 |. C9 leave
0040152A . C2 1000 retn 10
中间的子程序：
0040114E /$ 66:50 push ax
00401150 |. C0E8 04 shr al, 4
00401153 |. 24 0F and al, 0F
00401155 |. 04 30 add al, 30
00401157 |. 3C 39 cmp al, 39
00401159 |. 7E 02 jle short 0040115D
0040115B |. 04 07 add al, 7
0040115D |> 42 inc edx
0040115E |. 8882 70334000 mov byte ptr [edx+403370], al
00401164 |. 66:58 pop ax
00401166 |. C0E0 04 shl al, 4
00401169 |. C0E8 04 shr al, 4
0040116C |. 24 0F and al, 0F
0040116E |. 04 30 add al, 30
00401170 |. 3C 39 cmp al, 39
00401172 |. 7E 02 jle short 00401176
00401174 |. 04 07 add al, 7
00401176 |> 42 inc edx
00401177 |. 8882 70334000 mov byte ptr [edx+403370], al
0040117D . C3 retn
整体算法不困难，就是稍微有点复杂，有点耐心就可以搞定啦。
打开http://www.cnblogs.com/ZRBYYXDM/p/5115596.html中搭建的框架，新增类函数如下：
void CKengen_TemplateDlg::CreateStr(CString &str, DWORD num)
{
BYTE Temp = 0;
__asm{
push eax
mov eax,num
shr al,4
and al,0x0F
add al,0x30
cmp al,0x39
jle NotAdd
add al,7
NotAdd: mov Temp,al
pop eax
}
str += (char)Temp;
__asm{
push eax
mov eax,num
shl al,4
shr al,4
and al,0x0F
add al,0x30
cmp al,0x39
jle NotAdd2
add al,7
NotAdd2:mov Temp,al
pop eax
}
str += (char)Temp;
return ;
}
再将OnBtnDecrypt函数编辑如下：
void CKengen_TemplateDlg::OnBtnDecrypt()
{
// TODO: Add your control notification handler code here
CString str;
GetDlgItemText( IDC_EDIT_NAME,str ); //获取用户名字串基本信息。
int len = str.GetLength();
if ( len > 4 && len < 14 ){ //格式控制。
char CharArr[] = { 0x58,0x50,0x80,0x7C,0x05,0x01 };
char ComputerName[] = { 0x32,0x30,0x31,0x36,0x30,0x34,0x30,0x35,0x2D,0x32,0x30,0x30,0x37,0x00 };
DWORD CodeSegment[] = { 0x1D8A0C75, 0x00401207, 0x7575FB80, 0x00EBC303,
0x8068006A, 0x6A000000, 0x6A006A02, 0x00006800,
0x47684000, 0xE8004031, 0x00000337, 0x358DD88B,
0x0040390A, 0x00010468, 0x006A5600, 0x00033AE8,
};
CString Serial = "";
int i = 0,j = 0 ;
for ( ; i != str.GetLength() ; i++,j++ ){
DWORD Char = CharArr[j];
DWORD Temp = str.GetAt( i );
DWORD Res = 0;
Char = ( Char^0x12 ) + 0x34;
Temp = ( ((Temp<<3) - 0x20) ^ 0x66 );
__asm{
push eax
push ebx
mov eax,Char
mov ebx,Temp
xor al,bl
add eax,ebx
mov Res,eax
pop eax
pop ebx
}
CreateStr( Serial,Res );
if ( j == 3 )
j = -1;
}
Serial += "-";
CreateStr( Serial,0x536 );
CreateStr( Serial,0x505 );
Serial += "-";
for ( i = 0 ; i != 0x0D ; i++ ){
DWORD EAX = ( ComputerName[i] ^ CodeSegment[i] );
DWORD EBX = ( CodeSegment[i] ^ 0x0D ) - EAX - 0x0D;
DWORD Res = EAX + EBX;
CreateStr( Serial,Res );
}
SetDlgItemText( IDC_EDIT_PASSWORD,Serial );
}
else
MessageBox( "用户名格式错误！" );
}
再在OnInitDialog中添加此代码修改标题：SetWindowText(_T("CRACKME_Keygen"));
运行效果：
