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
mov esi, dword ptr [esp] (initial cpu selection)
push 0040313A kernel32.dll
push \eraser.bat
push \eraser.bat
0040125C push :loop\n\ndel "%s"\n\nif exist "%s" goto loop\n\ndel "%s"
push crackme# by d4ph1
0040128E push debugger found...i think im gonna kill myself!:(
004012A0 push \eraser.bat
push crackme# by d4ph1
0040134B push *======== your target is to create a valid keygenerator.contact : fistiks16@hotmail.com ========*
004014AB push crackme# by d4ph1
004014B0 push 004030E0 great work!hope this is coming from your keygenerator!:)
004014C0 push crackme# by d4ph1
004014C5 push this is not the right serial...
004014D5 push crackme# by d4ph1
004014DA push 004030BB you have to write a serial first...!
004014F3 push crackme# by d4ph1
004014F8 push you have to write a name first...!
push crackme# by d4ph1
0040150D push 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 /$ D1314000 push 004031D1 ; /isdebuggerpresent
004011F8 |. FF35 F0344000 push dword ptr [4034F0] ; |hModule = NULL
004011FE |. E8 8B030000 call <jmp.&kernel32.GetProcAddress> ; \GetProcAddress
|. FFD0 call eax
|. 0BC0 or eax, eax
|. 0C jnz short
|. 8A1D mov bl, byte ptr []
0040120F |. 80FB cmp bl,
|. jnz short
|. C3 retn
|> EB jmp short
|> 6A push ; /hTemplateFile = NULL
|. push ; |Attributes = NORMAL
0040121E |. 6A push ; |Mode = CREATE_ALWAYS
|. 6A push ; |pSecurity = NULL
|. 6A push ; |ShareMode = 0
|. push ; |Access = GENERIC_WRITE
|. push ; |\eraser.bat
0040122E |. E8 call <jmp.&kernel32.CreateFileA> ; \CreateFileA
|. 8BD8 mov ebx, eax
|. 8D35 0A394000 lea esi, dword ptr [40390A]
0040123B |. push ; /BufSize = 104 (260.)
|. push esi ; |PathBuffer => Crackme#.0040390A
|. 6A push ; |hModule = NULL
|. E8 3A030000 call <jmp.&kernel32.GetModuleFileName>; \GetModuleFileNameA
|. push esi ; /pDest => Crackme#.0040390A
|. push esi ; |pSrc => ""
0040124A |. E8 E5020000 call <jmp.&user32.CharToOemA> ; \CharToOemA
0040124F |. 8D3D 0A354000 lea edi, dword ptr [40350A]
|. push ; /\eraser.bat
0040125A |. push esi ; |<%s> => ""
0040125B |. push esi ; |<%s> => ""
0040125C |. push ; |:loop\n\ndel "%s"\n\nif exist "%s" goto loop\n\ndel "%s"
|. push edi ; |s => Crackme#.0040350A
|. E8 C7020000 call <jmp.&user32.wsprintfA> ; \wsprintfA
|. 83C4 add esp,
0040126A |. push edi ; /String
0040126B |. E8 3C030000 call <jmp.&kernel32.lstrlenA> ; \lstrlenA
|. 8D15 0E3A4000 lea edx, dword ptr [403A0E]
|. 6A push ; /pOverlapped = NULL
|. push edx ; |pBytesWritten => Crackme#.00403A0E
|. push eax ; |nBytesToWrite
0040127A |. push edi ; |Buffer
0040127B |. push ebx ; |hFile
0040127C |. E8 call <jmp.&kernel32.WriteFile> ; \WriteFile
|. push ebx ; /hObject
|. E8 DD020000 call <jmp.&kernel32.CloseHandle> ; \CloseHandle
|. 6A push ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
|. push ; |crackme#3 by d4ph1
0040128E |. push ; |debugger found...i think im gonna kill myself!:(
|. 6A push ; |hOwner = NULL
|. E8 B2020000 call <jmp.&user32.MessageBoxA> ; \MessageBoxA
0040129A |. 6A push ; /IsShown = 0
0040129C |. 6A push ; |DefDir = NULL
0040129E |. 6A push ; |Parameters = NULL
004012A0 |. push ; |\eraser.bat
004012A5 |. 6A push ; |Operation = NULL
004012A7 |. 6A push ; |hWnd = NULL
004012A9 |. E8 call <jmp.&shell32.ShellExecuteA> ; \ShellExecuteA
004012AE |. 6A push ; /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\CrackMe\crackme3selfdestructed\Crackme#3 - Self Destructed.exe"
IF EXIST "D:\IT\逆向工程\CrackMe\crackme3selfdestructed\Crackme#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：
|. EC314000 push 004031EC ; /123
0040136B |. push ; |wParam = 80
|. 6A 0D push 0D ; |Message = WM_GETTEXT
|. EA030000 push 3EA ; |ControlID = 3EA (1002.)
|. FF75 push dword ptr [ebp+] ; |hWnd
0040137A |. E8 D9010000 call <jmp.&user32.SendDlgItemMessageA>; \SendDlgItemMessageA
0040137F |. A3 6C324000 mov dword ptr [40326C], eax
|. 83F8 cmp eax, ; 长度低于等于4？
|. 0F86 jbe 004014ED ; 是则报错
0040138D |. 83F8 cmp eax, ; 长度高于等于14？
|. 0F83 jnb 004014ED ; 是则报错
|. push ; /lParam = 403270
0040139B |. push ; |wParam = 100
004013A0 |. 6A 0D push 0D ; |Message = WM_GETTEXT
004013A2 |. EB030000 push 3EB ; |ControlID = 3EB (1003.)
004013A7 |. FF75 push dword ptr [ebp+] ; |hWnd
004013AA |. E8 A9010000 call <jmp.&user32.SendDlgItemMessageA>; \SendDlgItemMessageA
004013AF |. 83F8 cmp eax, ; 长度为0则报错
004013B2 |. 0F84 1B010000 je 004014D3
004013B8 |. 33C9 xor ecx, ecx ; 开始初始化
004013BA |. 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 |. dec eax
004013C9 |. push eax
004013CA |> /inc esi
004013CB |. |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 |xor eax,
004013DD |. 83C0 |add eax,
004013E0 |. C1E3 |shl ebx,
004013E3 |. 83EB |sub ebx,
004013E6 |. 83F3 |xor ebx,
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 |. |pop eax
004013F3 |. 3BF0 |cmp esi, eax ; 是否已经遍历结束？
004013F5 |. |push eax
004013F6 |. 0A |je short
004013F8 |. 83F9 |cmp ecx, ; 第4次循环的时候，重置ecx为-1
004013FB |. |jnz short
004013FD |. 33C9 |xor ecx, ecx
004013FF |. |dec ecx
|>^ EB C8 \jmp short 004013CA
|> pop eax
|. inc edx
|. C682 >mov byte ptr [edx+], 2D ; 添加连字符-
0040140B |. 33C9 xor ecx, ecx
0040140D |. dec ecx
0040140E |. BB mov ebx,
|. 33C0 xor eax, eax
|> /inc ecx
|. 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
|. 2BFE |sub edi, esi
|. 03C7 |add eax, edi
|. 2BC6 |sub eax, esi
0040142A |. C1E0 |shl eax,
0040142D |. 83F9 |cmp ecx, ; 循环两次了？
|.^ E3 \jnz short
|. C1E8 shr eax,
|. 33C9 xor ecx, ecx
|. dec ecx
|> /inc ecx
|. 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
|. 83F9 |cmp ecx, ; 循环两次了？
|.^ F3 \jnz short
|. inc edx
|. C682 >mov byte ptr [edx+], 2D ; 添加连字符-
0040144D |. 33C9 xor ecx, ecx
0040144F |. dec ecx
|. 33FF xor edi, edi
|. 0FBE35 >movsx esi, byte ptr []
|> /inc ecx
0040145A |. 0FBE81 F63440>|movsx eax, byte ptr [ecx+4034F6] ; 遍历一个特定字符串
|. 8B9F |mov ebx, dword ptr [edi+] ; 遍历一个代码区段
|. 33C3 |xor eax, ebx
|. 331D |xor ebx, dword ptr []
0040146F |. 2BD8 |sub ebx, eax
|. 2B1D |sub ebx, dword ptr []
|. 03C3 |add eax, ebx
|. E8 D0FCFFFF |call 0040114E ; 根据eax的值算出一个对应的值，并保存
0040147E |. 83C7 |add edi,
|. 4E |dec esi ; 循环结束？
|.^ D5 \jnz short
|. push ; /String = ""
|. E8 1E010000 call <jmp.&kernel32.lstrlenA> ; \lstrlenA
0040148E |. 8BC8 mov ecx, eax
|. inc ecx
|> /dec ecx ; 密码和序列号是否一致？
|. 0FBE81 >|movsx eax, byte ptr [ecx+]
|. 0FBE99 >|movsx ebx, byte ptr [ecx+]
004014A0 |. 3BC3 |cmp eax, ebx
004014A2 |. 1A |jnz short 004014BE
004014A4 |. 83F9 |cmp ecx,
004014A7 |.^ E8 \jnz short
004014A9 |. 6A push ; /Style = MB_OK|MB_APPLMODAL
004014AB |. push ; |crackme#3 by d4ph1
004014B0 |. E0304000 push 004030E0 ; |great work!hope this is coming from your keygenerator!:)
004014B5 |. 6A push ; |hOwner = NULL
004014B7 |. E8 call <jmp.&user32.MessageBoxA> ; \MessageBoxA
004014BC |. EB jmp short 004014E6
004014BE |> 6A push ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
004014C0 |. push ; |crackme#3 by d4ph1
004014C5 |. push ; |this is not the right serial...
004014CA |. 6A push ; |hOwner = NULL
004014CC |. E8 7B000000 call <jmp.&user32.MessageBoxA> ; \MessageBoxA
004014D1 |. EB jmp short 004014E6
004014D3 |> 6A push ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
004014D5 |. push ; |crackme#3 by d4ph1
004014DA |. BB304000 push 004030BB ; |you have to write a serial first...!
004014DF |. 6A push ; |hOwner = NULL
004014E1 |. E8 call <jmp.&user32.MessageBoxA> ; \MessageBoxA
004014E6 |> E8 93FCFFFF call 0040117E
004014EB |. EB 2C jmp short
004014ED |> 0BC0 or eax, eax
004014EF |. jnz short
004014F1 |. 6A push ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
004014F3 |. push ; |crackme#3 by d4ph1
004014F8 |. push ; |you have to write a name first...!
004014FD |. 6A push ; |hOwner = NULL
004014FF |. E8 call <jmp.&user32.MessageBoxA> ; \MessageBoxA
|. EB jmp short
|> 6A push ; /Style = MB_OK|MB_ICONHAND|MB_APPLMODAL
|. push ; |crackme#3 by d4ph1
0040150D |. push ; |the name you write is not correct!
|. 6A push ; |hOwner = NULL
|. E8 call <jmp.&user32.MessageBoxA> ; \MessageBoxA
|> EB jmp short
0040151B |> B8 mov eax,
|. C9 leave
|. C2 retn
|> B8 mov eax,
|. C9 leave
0040152A \. C2 retn
中间的子程序：
0040114E /$ : push ax
|. C0E8 shr al,
|. 0F and al, 0F
|. add al,
|. 3C cmp al,
|. 7E jle short 0040115D
0040115B |. add al,
0040115D |> inc edx
0040115E |. mov byte ptr [edx+], al
|. : pop ax
|. C0E0 shl al,
|. C0E8 shr al,
0040116C |. 0F and al, 0F
0040116E |. add al,
|. 3C cmp al,
|. 7E jle short
|. add al,
|> inc edx
|. mov byte ptr [edx+], 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 = ; __asm{
push eax mov eax,num
shr al,
and al,0x0F
add al,0x30
cmp al,0x39
jle NotAdd
add al,
NotAdd: mov Temp,al pop eax
} str += (char)Temp; __asm{
push eax mov eax,num
shl al,
shr al,
and al,0x0F
add al,0x30
cmp al,0x39
jle NotAdd2
add al,
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 > && len < ){ //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 = ,j = ;
for ( ; i != str.GetLength() ; i++,j++ ){
DWORD Char = CharArr[j];
DWORD Temp = str.GetAt( i );
DWORD Res = ; Char = ( Char^0x12 ) + 0x34;
Temp = ( ((Temp<<) - 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 == )
j = -;
} Serial += "-";
CreateStr( Serial,0x536 );
CreateStr( Serial,0x505 );
Serial += "-"; for ( i = ; 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：