目标软件:天然码输入法(对应小球兄昨天的帖子)
目标文件:trm32.ime;getdiskserial.exe
加壳方式:UPX 1.03
使用工具:trw2000
Procdump
peditor
Imprec 1.3
URL: http://www.chinatrm.com/download/file/suggest/setup.exe
本文作者:leo_cyl
加密特点:在比较注册码前,先产生另外的进程调用vxd绕过window api读指纹盘,如果没有指纹盘就不比较注册码。其实这个软件是明码比较不用脱壳的,但对dll脱壳是很多初学者还没掌握的基本技能,所以还是多此一举把trm32.ime的壳脱了。(trm32.ime说穿了就是一个dll)
dll壳脱的难点在于dll是动态加载的(废话!),所以不能用loader。那么我们只好在dll的entry point加上int 3的指令了。
用peditor装入\windows\system\trm32.ime,可看到entry point = 0003D210;Image Base = 10000000;用peditor的FLC计算entry point(1003d210)的偏移为:00013610。再用二进制编辑器在偏移为00013610处机器码为80H的内容改为CC(即 int 3的机器码)。
现在运行trw2k,下命令“I3HERE ON”,打开任务条的输入法管理器。选天然码,点“属性”将激活trw2k,停在dll的入口处:
017F:1003D210 CC INT3
017F:1003D211 7C24 JL 1003D237 (NO JUMP)
017F:1003D213 0801 OR [ECX],AL
017F:1003D215 0F8581010000 JNZ NEAR 1003D39C
017F:1003D21B 60 PUSHA
017F:1003D21C BE00A00210 MOV ESI,1002A000
“r eip eip-1”,“d eip”,将017F:1003D210处改为80H:
017F:1003D210 807C240801 CMP BYTE [ESP+08],01
017F:1003D215 0F8581010000 JNZ NEAR 1003D39C
017F:1003D21B 60 PUSHA
017F:1003D21C BE00A00210 MOV ESI,1002A000
017F:1003D221 8DBE0070FDFF LEA EDI,[ESI+FFFD7000]
017F:1003D227 57 PUSH EDI
f10跟踪,来到这里:
017F:1003D344 95 XCHG EAX,EBP
017F:1003D345 8A07 MOV AL,[EDI]
017F:1003D347 47 INC EDI 《===EDI为引入的函数名
017F:1003D348 08C0 OR AL,AL
017F:1003D34A 74DC JZ 1003D328
017F:1003D34C 89F9 MOV ECX,EDI
017F:1003D34E 57 PUSH EDI
017F:1003D34F 48 DEC EAX
017F:1003D350 F2AE REPNE SCASB
017F:1003D352 55 PUSH EBP
017F:1003D353 FF9634DA0300 CALL NEAR [ESI+0003DA34] 〈==getprocessaddress
017F:1003D359 09C0 OR EAX,EAX
017F:1003D35B 7407 JZ 1003D364
017F:1003D35D 8903 MOV [EBX],EAX
017F:1003D35F 83C304 ADD EBX,BYTE +04
017F:1003D362 EBE1 JMP SHORT 1003D345
以上代码为恢复引入表。继续f10跟踪,来到这里:
017F:1003D38C EBE2 JMP SHORT 1003D370
017F:1003D38E 240F AND AL,0F
017F:1003D390 C1E010 SHL EAX,10
017F:1003D393 668B07 MOV AX,[EDI]
017F:1003D396 83C702 ADD EDI,BYTE +02
017F:1003D399 EBE2 JMP SHORT 1003D37D
017F:1003D39B 61 POPA 〈====很眼熟吧!
017F:1003D39C E906BBFCFF JMP 10008EA7〈====OEP
所以OEP在10008EA7处。在10008EA7处DUMP出文件。先看一下trm32.ime的IMTE。“MOD32 TRM32.IME”
可看到IMTE 为:xxxxxxxx;“PEDUMP C:\TRM32.DLL xxxxxxxx”。并挂起进程“SUSPEND”。
回到window运行Imprec 1.3。在任务列表选rundll32.exe 点“pick dll”找到trm32.ime。输入OEP(8EA7)
“get Imports”可修复IAT。再“fix dump”。将产生TRM32_.DLL,把它改名为trm32.ime 即可。到此脱壳完成。
用dump出的trm32.ime替换原来的文件。再次运行输入法管理器。选天然码,点“属性”,将弹出MESSAGEBOX说没有指纹盘或disk serial不对。control-n激活trw2k,“pmodule”,“确定”后,回到trw2k:
:00401514 89442410 mov dword ptr [esp+10], eax
:00401518 8B442434 mov eax, dword ptr [esp+34]
:0040151C 50 push eax
:0040151D E88EFCFFFF call 004011B0 〈=====进入
:00401522 8BD8 mov ebx, eax
:00401524 3BDE cmp ebx, esi
:00401526 7528 jne 00401550
:00401528 56 push esi
* Possible StringData Ref from Data Obj ->"DiskSerial"
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:00401529 68DC704000 push 004070DC
:0040152E B8847F4000 mov eax, 00407F84
* Possible StringData Ref from Data Obj ->"Disk not exists or process failed "
->"!"
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:00401533 68B8704000 push 004070B8
:00401538 56 push esi
:00401539 89442424 mov dword ptr [esp+24], eax
:0040153D 89442428 mov dword ptr [esp+28], eax
:00401541 89442420 mov dword ptr [esp+20], eax
* Reference To: USER32.MessageBoxA, Ord:01BEh
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:00401545 FF15C8604000 Call dword ptr [004060C8]
:0040154B E9A1000000 jmp 004015F1
注意这时是在getdiskserial.exe的领空。(也就是说trm32.ime产生getdiskserial.exe进程)。往上看,注意0040151D处的call 004011B0,在此处下断点,再次运行进入“call 004011B0”来到这:
017F:00401439 50 PUSH EAX
017F:0040143A 8D8C2488030000 LEA ECX,[ESP+0388]
017F:00401441 6A04 PUSH BYTE +04
017F:00401443 51 PUSH ECX
017F:00401444 6A00 PUSH BYTE +00
017F:00401446 6A00 PUSH BYTE +00
017F:00401448 6A01 PUSH BYTE +01
017F:0040144A 56 PUSH ESI
017F:0040144B FF1514604000 CALL `KERNEL32!DeviceIoControl` 〈=调用vxd
017F:00401451 56 PUSH ESI
017F:00401452 FF151C604000 CALL `KERNEL32!FindCloseChangeNotification`
017F:00401458 8BB42490130000 MOV ESI,[ESP+1390]
017F:0040145F 8A843484030000 MOV AL,[ESP+ESI+0384]
017F:00401466 84C0 TEST AL,AL 〈==是否有指纹盘或disk serial ?
017F:00401468 744D JZ 004014B7 〈==没有就跳
017F:0040146A 8BC6 MOV EAX,ESI
017F:0040144B处调用diskserial.vxd绝对读磁盘,017F:00401468处是判断。因为没有指纹盘,将此处改为nop;nop;替换getdiskserial.exe(在window的system下)。
再次运行,这次可以来到“属性”窗口,点“确定”可来到注册窗口,我的机器码为123456789012,输入用户名leo_cyl,注册码12121212。下断点hmemcpy,跟踪来到这里:
:10001FC2 8D4C240C lea ecx, dword ptr [esp+0C]
:10001FC6 8D542414 lea edx, dword ptr [esp+14]
:10001FCA 51 push ecx
:10001FCB 8D442434 lea eax, dword ptr [esp+34]
:10001FCF 52 push edx
:10001FD0 50 push eax
:10001FD1 E85A5E0000 call 10007E30
:10001FD6 83C40C add esp, 0000000C
:10001FD9 E822600000 call 10008000 《=====注意
:10001FDE A1ACF90110 mov eax, dword ptr [1001F9AC]
:10001FE3 6A00 push 00000000
:10001FE5 85C0 test eax, eax
:10001FE7 7425 je 1000200E 〈===跳的话就注册失败
:10001FE9 6878F10010 push 1000F178
:10001FEE 686CF10010 push 1000F16C
:10001FF3 56 push esi
* Reference To: user32.MessageBoxA, Ord:01B7h
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:10001FF4 FF15A0D10010 Call dword ptr [1000D1A0]
:10001FFA 6A01 push 00000001
:10001FFC 56 push esi
* Reference To: user32.EndDialog, Ord:00B9h
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:10001FFD FF1590D20010 Call dword ptr [1000D290]
:10002003 5F pop edi
:10002004 5E pop esi
:10002005 33C0 xor eax, eax
:10002007 5B pop ebx
:10002008 83C438 add esp, 00000038
:1000200B C21000 ret 0010
进入:10001FD9 处的call 10008000:
。。。。。
。。。。。
:10008038 894C2450 mov dword ptr [esp+50], ecx
:1000803C 89542410 mov dword ptr [esp+10], edx
:10008040 89442420 mov dword ptr [esp+20], eax
:10008044 894C2454 mov dword ptr [esp+54], ecx
:10008048 56 push esi
:10008049 6689542418 mov word ptr [esp+18], dx
:1000804E 6689442428 mov word ptr [esp+28], ax
:10008053 66894C245C mov word ptr [esp+5C], cx
:10008058 57 push edi
:10008059 8854241E mov byte ptr [esp+1E], dl
:1000805D 8844242E mov byte ptr [esp+2E], al
:10008061 884C2462 mov byte ptr [esp+62], cl
:10008065 E826A4FFFF call 10002490 〈======注意此call
:1000806A 8BF8 mov edi, eax
:1000806C 83C9FF or ecx, FFFFFFFF
:1000806F 33C0 xor eax, eax
:10008071 8D542410 lea edx, dword ptr [esp+10]
:10008075 F2 repnz
:10008076 AE scasb
:10008077 F7D1 not ecx
10008065 处的call将调用ShellExecuteA的window api 产生getdiskserial.exe进程。假设刚才没改getdiskserial.exe的话,有两个进程要跟踪,比较麻烦,如果非法用户的话getdiskserial将弹出MESSAGEBOX,注册失败。
继续跟踪来到这里:
* Referenced by a (U)nconditional or (C)onditional Jump at Address:
|:10008191(C)
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:1000817D 8A540430 mov dl, byte ptr [esp+eax+30] 〈==这是假注册码
:10008181 8A4C0468 mov cl, byte ptr [esp+eax+68] 〈==正确注册码
:10008185 3AD1 cmp dl, cl
:10008187 0F851BFFFFFF jne 100080A8
:1000818D 40 inc eax
:1000818E 83F809 cmp eax, 00000009
:10008191 7CEA jl 1000817D
:10008193 5F pop edi
:10008194 C705ACF9011001000000 mov dword ptr [1001F9AC], 00000001
:1000819E 5E pop esi
:1000819F 81C480000000 add esp, 00000080
:100081A5 C3 ret
“d esp+eax+68”将看到正确注册码:2023252219。
到此pj完成。打了那么多字,好累啊!(随便说一句这个输入法我一点也不喜欢,呵呵……)
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