发信人: kouji(小雪・新生), 信区: Crack
标 题: 已经初步搞定,dog学长给我点指导吧~
发信站: 饮水思源 (2006年04月08日02:05:48 星期六)
根本没有技术含量,此次操作就用了F7,F8和“bp MessageBoxA”,当然还有眼睛和脑袋
。
由于初学crack,看了前几天上面转看雪的crackme教程,于是自己动手试了试:
1. 文件解密失败会弹出一个MessageBox,于是就下了断点,不过发现向上看了半天没看明
白,猜测大概离关键代码太远。
2. 未解密文件当对它解密时会弹出MessageBox,确定处理下一步,取消cancel掉整个操作
,于是我做了这么个假设:在第一个文件处理完毕,应该跳出关键代码,然后点确定应该
进入下一个处理,也就是说,可以找到关键代码的入口,而出口就是解密失败的那个Mess
ageBox。范围应该就是这点。
3. 由于实在技术太烂,决定走一次成功走一次失败,查看JNZ/JE之类的跳转情况,但是结
果令我失望:完全一样-_-。一定是哪里弄错了。
4. 苦想了一会儿,发现另一个突破点:解密成功会生成结果文件,于是一个一个call的跳
,终于找到一个生成文件的call,当然我也只是猜测,因为不能保证这个是关键代码,但
事实证明我运气比较好。
5. 进去以后依然没辄...继续一次正确一次失败看条件。终于找到一个不一样的:
call XXXXXXXX
jz XXXXXXXX
汇编基础不好,猜猜大概是判断返回是否为零,那么我猜应该是一个函数传进去几个参数
判断是否正确吧。
6. 结果我运气特别好,检查参数的时候发现送进去的就是源密码地址和输入密码的地址,
用眼睛看一下...马马乎乎可以解决文件加密问题了-_-
见笑了^_^ 头一次破解~
下面是DUMP关键代码的汇编:
004AA71C /$ 55 push ebp
004AA71D |. 8BEC mov ebp,esp
004AA71F |. 51 push ecx
004AA720 |. B9 09000000 mov ecx,9
004AA725 |> 6A 00 /push 0
004AA727 |. 6A 00 |push 0
004AA729 |. 49 |dec ecx
004AA72A |.^ 75 F9 \jnz short WomEncry.004AA725
004AA72C |. 51 push ecx
004AA72D |. 874D FC xchg dword ptr ss:[ebp-4],ecx
004AA730 |. 53 push ebx
004AA731 |. 56 push esi
004AA732 |. 894D F8 mov dword ptr ss:[ebp-8],ecx
004AA735 |. 8955 FC mov dword ptr ss:[ebp-4],edx
004AA738 |. 8BF0 mov esi,eax
004AA73A |. 8B45 FC mov eax,dword ptr ss:[ebp-4]
004AA73D |. E8 06A3F5FF call WomEncry.00404A48
004AA742 |. 8B45 F8 mov eax,dword ptr ss:[ebp-8]
004AA745 |. E8 FEA2F5FF call WomEncry.00404A48
004AA74A |. 33C0 xor eax,eax
004AA74C |. 55 push ebp
004AA74D |. 68 EFA94A00 push WomEncry.004AA9EF
004AA752 |. 64:FF30 push dword ptr fs:[eax]
004AA755 |. 64:8920 mov dword ptr fs:[eax],esp
004AA758 |. 33DB xor ebx,ebx
004AA75A |. 8D55 E8 lea edx,dword ptr ss:[ebp-18]
004AA75D |. 8B45 FC mov eax,dword ptr ss:[ebp-4]
004AA760 |. E8 03EAF5FF call WomEncry.00409168
004AA765 |. 8B45 E8 mov eax,dword ptr ss:[ebp-18]
004AA768 |. 8D55 F4 lea edx,dword ptr ss:[ebp-C]
004AA76B |. E8 54E0F5FF call WomEncry.004087C4
004AA770 |. 8B45 F4 mov eax,dword ptr ss:[ebp-C]
004AA773 |. BA 08AA4A00 mov edx,WomEncry.004AAA08 ; ASCII ".exe"
004AA778 |. E8 27A2F5FF call WomEncry.004049A4
004AA77D |. 74 22 je short WomEncry.004AA7A1
004AA77F |. 8B45 F4 mov eax,dword ptr ss:[ebp-C]
004AA782 |. BA 18AA4A00 mov edx,WomEncry.004AAA18 ; ASCII ".com"
004AA787 |. E8 18A2F5FF call WomEncry.004049A4
004AA78C |. 74 13 je short WomEncry.004AA7A1
004AA78E |. 8B45 F4 mov eax,dword ptr ss:[ebp-C]
004AA791 |. BA 28AA4A00 mov edx,WomEncry.004AAA28 ; ASCII ".bat"
004AA796 |. E8 09A2F5FF call WomEncry.004049A4
004AA79B |. 0F85 860000>jnz WomEncry.004AA827
004AA7A1 |> 8D45 E4 lea eax,dword ptr ss:[ebp-1C]
004AA7A4 |. B9 38AA4A00 mov ecx,WomEncry.004AAA38
004AA7A9 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA7AC |. E8 F3A0F5FF call WomEncry.004048A4
004AA7B1 |. 8B55 E4 mov edx,dword ptr ss:[ebp-1C]
004AA7B4 |. 8B45 FC mov eax,dword ptr ss:[ebp-4]
004AA7B7 |. E8 30FEFFFF call WomEncry.004AA5EC
004AA7BC |. 84C0 test al,al
004AA7BE |. 74 35 je short WomEncry.004AA7F5
004AA7C0 |. 6A 03 push 3
004AA7C2 |. 8D45 EC lea eax,dword ptr ss:[ebp-14]
004AA7C5 |. 50 push eax
004AA7C6 |. 8D45 E0 lea eax,dword ptr ss:[ebp-20]
004AA7C9 |. B9 44AA4A00 mov ecx,WomEncry.004AAA44 ; ASCII "e0"
004AA7CE |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA7D1 |. E8 CEA0F5FF call WomEncry.004048A4
004AA7D6 |. 8B45 E0 mov eax,dword ptr ss:[ebp-20]
004AA7D9 |. 50 push eax
004AA7DA |. 8D45 DC lea eax,dword ptr ss:[ebp-24]
004AA7DD |. B9 38AA4A00 mov ecx,WomEncry.004AAA38
004AA7E2 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA7E5 |. E8 BAA0F5FF call WomEncry.004048A4
004AA7EA |. 8B55 DC mov edx,dword ptr ss:[ebp-24]
004AA7ED |. 8BC6 mov eax,esi
004AA7EF |. 59 pop ecx
004AA7F0 |. E8 F3F7FFFF call WomEncry.004A9FE8
004AA7F5 |> 8D45 D8 lea eax,dword ptr ss:[ebp-28]
004AA7F8 |. B9 38AA4A00 mov ecx,WomEncry.004AAA38
004AA7FD |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA800 |. E8 9FA0F5FF call WomEncry.004048A4
004AA805 |. 8B45 D8 mov eax,dword ptr ss:[ebp-28]
004AA808 |. E8 2BE8F5FF call WomEncry.00409038
004AA80D |. 8D45 D4 lea eax,dword ptr ss:[ebp-2C]
004AA810 |. B9 44AA4A00 mov ecx,WomEncry.004AAA44 ; ASCII "e0"
004AA815 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA818 |. E8 87A0F5FF call WomEncry.004048A4
004AA81D |. 8B45 D4 mov eax,dword ptr ss:[ebp-2C]
004AA820 |. E8 13E8F5FF call WomEncry.00409038
004AA825 |. EB 23 jmp short WomEncry.004AA84A
004AA827 |> 6A 03 push 3
004AA829 |. 8D45 EC lea eax,dword ptr ss:[ebp-14]
004AA82C |. 50 push eax
004AA82D |. 8D45 D0 lea eax,dword ptr ss:[ebp-30]
004AA830 |. B9 38AA4A00 mov ecx,WomEncry.004AAA38
004AA835 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA838 |. E8 67A0F5FF call WomEncry.004048A4
004AA83D |. 8B4D D0 mov ecx,dword ptr ss:[ebp-30]
004AA840 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA843 |. 8BC6 mov eax,esi
004AA845 |. E8 9EF7FFFF call WomEncry.004A9FE8
004AA84A |> 8B45 EC mov eax,dword ptr ss:[ebp-14]
004AA84D |. 8B55 F8 mov edx,dword ptr ss:[ebp-8]
004AA850 |. E8 4FA1F5FF call WomEncry.004049A4
004AA855 |. 74 45 je short WomEncry.004AA89C
004AA857 |. 8B45 F8 mov eax,dword ptr ss:[ebp-8]
004AA85A |. BA 50AA4A00 mov edx,WomEncry.004AAA50 ; ASCII "Lujin-
Wom"
004AA85F |. E8 40A1F5FF call WomEncry.004049A4
004AA864 |. 74 36 je short WomEncry.004AA89C
004AA866 |. 6A 10 push 10
004AA868 |. 68 5CAA4A00 push WomEncry.004AAA5C
004AA86D |. 68 6CAA4A00 push WomEncry.004AAA6C
004AA872 |. 8BC6 mov eax,esi
004AA874 |. E8 6709FCFF call WomEncry.0046B1E0
004AA879 |. 50 push eax ; |hOwner
004AA87A |. E8 69CAF5FF call <jmp.&user32.MessageBoxA> ; \MessageBoxA
004AA87F |. 8D45 CC lea eax,dword ptr ss:[ebp-34]
004AA882 |. B9 A0AA4A00 mov ecx,WomEncry.004AAAA0 ; ASCII "wom"
004AA887 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA88A |. E8 15A0F5FF call WomEncry.004048A4
004AA88F |. 8B45 CC mov eax,dword ptr ss:[ebp-34]
004AA892 |. E8 A1E7F5FF call WomEncry.00409038
004AA897 |. E9 38010000 jmp WomEncry.004AA9D4
004AA89C |> 8B45 F4 mov eax,dword ptr ss:[ebp-C]
004AA89F |. BA 08AA4A00 mov edx,WomEncry.004AAA08 ; ASCII ".exe"
004AA8A4 |. E8 FBA0F5FF call WomEncry.004049A4
004AA8A9 |. 74 22 je short WomEncry.004AA8CD
004AA8AB |. 8B45 F4 mov eax,dword ptr ss:[ebp-C]
004AA8AE |. BA 18AA4A00 mov edx,WomEncry.004AAA18 ; ASCII ".com"
004AA8B3 |. E8 ECA0F5FF call WomEncry.004049A4
004AA8B8 |. 74 13 je short WomEncry.004AA8CD
004AA8BA |. 8B45 F4 mov eax,dword ptr ss:[ebp-C]
004AA8BD |. BA 28AA4A00 mov edx,WomEncry.004AAA28 ; ASCII ".bat"
004AA8C2 |. E8 DDA0F5FF call WomEncry.004049A4
004AA8C7 |. 0F85 A70000>jnz WomEncry.004AA974
004AA8CD |> 8D45 C8 lea eax,dword ptr ss:[ebp-38]
004AA8D0 |. B9 A0AA4A00 mov ecx,WomEncry.004AAAA0 ; ASCII "wom"
004AA8D5 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA8D8 |. E8 C79FF5FF call WomEncry.004048A4
004AA8DD |. 8B55 C8 mov edx,dword ptr ss:[ebp-38]
004AA8E0 |. 8B45 FC mov eax,dword ptr ss:[ebp-4]
004AA8E3 |. E8 D4FBFFFF call WomEncry.004AA4BC
004AA8E8 |. 84C0 test al,al
004AA8EA |. 0F84 E40000>je WomEncry.004AA9D4
004AA8F0 |. 6A 01 push 1
004AA8F2 |. 8D45 F0 lea eax,dword ptr ss:[ebp-10]
004AA8F5 |. 50 push eax
004AA8F6 |. 8D45 C4 lea eax,dword ptr ss:[ebp-3C]
004AA8F9 |. B9 ACAA4A00 mov ecx,WomEncry.004AAAAC ; ASCII "wome"
004AA8FE |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA901 |. E8 9E9FF5FF call WomEncry.004048A4
004AA906 |. 8B45 C4 mov eax,dword ptr ss:[ebp-3C]
004AA909 |. 50 push eax
004AA90A |. 8D45 C0 lea eax,dword ptr ss:[ebp-40]
004AA90D |. B9 A0AA4A00 mov ecx,WomEncry.004AAAA0 ; ASCII "wom"
004AA912 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA915 |. E8 8A9FF5FF call WomEncry.004048A4
004AA91A |. 8B55 C0 mov edx,dword ptr ss:[ebp-40]
004AA91D |. 8BC6 mov eax,esi
004AA91F |. 59 pop ecx
004AA920 |. E8 C3F6FFFF call WomEncry.004A9FE8
004AA925 |. 8B55 F0 mov edx,dword ptr ss:[ebp-10]
004AA928 |. B8 BCAA4A00 mov eax,WomEncry.004AAABC ; ASCII "True->
"
004AA92D |. E8 6AA2F5FF call WomEncry.00404B9C
004AA932 |. 85C0 test eax,eax
004AA934 |. 74 24 je short WomEncry.004AA95A
004AA936 |. A1 10F04A00 mov eax,dword ptr ds:[4AF010]
004AA93B |. 8038 00 cmp byte ptr ds:[eax],0
004AA93E |. 74 18 je short WomEncry.004AA958
004AA940 |. 8D45 BC lea eax,dword ptr ss:[ebp-44]
004AA943 |. B9 CCAA4A00 mov ecx,WomEncry.004AAACC ; ASCII ".bak"
004AA948 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA94B |. E8 549FF5FF call WomEncry.004048A4
004AA950 |. 8B45 BC mov eax,dword ptr ss:[ebp-44]
004AA953 |. E8 E0E6F5FF call WomEncry.00409038
004AA958 |> B3 01 mov bl,1
004AA95A |> 8D45 B8 lea eax,dword ptr ss:[ebp-48]
004AA95D |. B9 A0AA4A00 mov ecx,WomEncry.004AAAA0 ; ASCII "wom"
004AA962 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA965 |. E8 3A9FF5FF call WomEncry.004048A4
004AA96A |. 8B45 B8 mov eax,dword ptr ss:[ebp-48]
004AA96D |. E8 C6E6F5FF call WomEncry.00409038
004AA972 |. EB 60 jmp short WomEncry.004AA9D4
004AA974 |> 6A 01 push 1
004AA976 |. 8D45 F0 lea eax,dword ptr ss:[ebp-10]
004AA979 |. 50 push eax
004AA97A |. 8D45 B4 lea eax,dword ptr ss:[ebp-4C]
004AA97D |. B9 ACAA4A00 mov ecx,WomEncry.004AAAAC ; ASCII "wome"
004AA982 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA985 |. E8 1A9FF5FF call WomEncry.004048A4
004AA98A |. 8B4D B4 mov ecx,dword ptr ss:[ebp-4C]
004AA98D |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA990 |. 8BC6 mov eax,esi
004AA992 |. E8 51F6FFFF call WomEncry.004A9FE8
004AA997 |. 8B55 F0 mov edx,dword ptr ss:[ebp-10]
004AA99A |. B8 BCAA4A00 mov eax,WomEncry.004AAABC ; ASCII "True->
"
004AA99F |. E8 F8A1F5FF call WomEncry.00404B9C
004AA9A4 |. 85C0 test eax,eax
004AA9A6 |. 74 14 je short WomEncry.004AA9BC
004AA9A8 |. A1 10F04A00 mov eax,dword ptr ds:[4AF010]
004AA9AD |. 8038 00 cmp byte ptr ds:[eax],0
004AA9B0 |. 74 08 je short WomEncry.004AA9BA
004AA9B2 |. 8B45 FC mov eax,dword ptr ss:[ebp-4]
004AA9B5 |. E8 7EE6F5FF call WomEncry.00409038
004AA9BA |> B3 01 mov bl,1
004AA9BC |> 8D45 B0 lea eax,dword ptr ss:[ebp-50]
004AA9BF |. B9 A0AA4A00 mov ecx,WomEncry.004AAAA0 ; ASCII "wom"
004AA9C4 |. 8B55 FC mov edx,dword ptr ss:[ebp-4]
004AA9C7 |. E8 D89EF5FF call WomEncry.004048A4
004AA9CC |. 8B45 B0 mov eax,dword ptr ss:[ebp-50]
004AA9CF |. E8 64E6F5FF call WomEncry.00409038
004AA9D4 |> 33C0 xor eax,eax
004AA9D6 |. 5A pop edx
004AA9D7 |. 59 pop ecx
004AA9D8 |. 59 pop ecx
004AA9D9 |. 64:8910 mov dword ptr fs:[eax],edx
004AA9DC |. 68 F6A94A00 push WomEncry.004AA9F6
004AA9E1 |> 8D45 B0 lea eax,dword ptr ss:[ebp-50]
004AA9E4 |. BA 14000000 mov edx,14
004AA9E9 |. E8 CE9BF5FF call WomEncry.004045BC
004AA9EE \. C3 retn
--
小雪的七宗罪
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