TDOH 南區 WorkShop 2016 Reversing on Windows

Reversing about PE (portable-executable) and cracking on Windows for education.

Transcript

1. aaaddress1 at The Declaration of Hacker (TDOH) Reversing On WINDOWS
2. aaaddress1 at The Declaration of Hacker (TDOH) Who Am I
3. aaaddress1 at The Declaration of Hacker (TDOH) ⾺聖豪 (aaaddress1, aka adr) 義守⼤學資訊⼯程三年級 Reverse Engineering, Pwn C/C++, C#, x86, Node.js Blog: Adr.Horse, 30cm.tw Speaker ✓ HITCON 2015 ✓ SITCON 2016 ✓ Besides Las Vegas 2016 ✓ TDOHxNTSTU Security Lecture Reversing Windows Pwn
4. aaaddress1 at The Declaration of Hacker (TDOH) MapleHack CrackShield Tower Of Savior Hack Adr’s FB Isu.30cm.tw AIDS PykemonGo, MadPocket My Little Ransomware
5. aaaddress1 at The Declaration of Hacker (TDOH) introduction
6. aaaddress1 at The Declaration of Hacker (TDOH) 這是⼀一場屬於⼯工具⼈人 C/C++ 的開發⾃自我修養
7. aaaddress1 at The Declaration of Hacker (TDOH) 今天務必保持清醒！
8. aaaddress1 at The Declaration of Hacker (TDOH) 此議程內容需要⼤大量量艱深 C/C++ 開發底⼦子 如有任何問題請立即舉⼿手 break; 我！
9. aaaddress1 at The Declaration of Hacker (TDOH) Trial https://goo.gl/ky7SsW Slide https://goo.gl/HBLtkm
10. aaaddress1 at The Declaration of Hacker (TDOH) Outline
11. aaaddress1 at The Declaration of Hacker (TDOH) Requirement ✓IDA (Pro) ✓OllyDbg ✓Cheat Engine ✓Windows7 x86 ✓Dev C++
12. aaaddress1 at The Declaration of Hacker (TDOH) Windows PE & Process ✓Have fun in PE structure ✓Import Address Table (IAT) ✓ImageBase & Find the entry
13. aaaddress1 at The Declaration of Hacker (TDOH) Assembly ✓sizeof( variable ) ✓eax, ebx, ecx, edx, etc ✓add, sub, inc, dec ✓xor ✓Flag & Branch ✓Loop ✓x86 Calling Convention Function Call esp & ebp
14. aaaddress1 at The Declaration of Hacker (TDOH) Analyzer ✓IDA (Pro) PE, IAT, EAT Strings List Flow Chart Function & Variable Anti-Trace ✓OllyDbg Create Process & Attach Hook & Trace ✓Cheat Engine Create Process & Attach Memory Scan for data Hook & Trace
15. aaaddress1 at The Declaration of Hacker (TDOH) Bonus ✓IDA Dynamic Analysis ✓Patch Executable file patch Dynamic Patch ✓Cheat Engine PE View ✓Assembly & Special
16. aaaddress1 at The Declaration of Hacker (TDOH) Portable Executable
17. aaaddress1 at The Declaration of Hacker (TDOH)
18. aaaddress1 at The Declaration of Hacker (TDOH) Return 0 for what?
19. aaaddress1 at The Declaration of Hacker (TDOH) View → Open subviews → Proximity browser IDA
20. aaaddress1 at The Declaration of Hacker (TDOH) IDA
21. aaaddress1 at The Declaration of Hacker (TDOH) IDA
22. aaaddress1 at The Declaration of Hacker (TDOH) IDA The return value of main function is the ‘Exit Status’
23. aaaddress1 at The Declaration of Hacker (TDOH) IDA PE Loader will find ‘_start’ function from Exports Address Table (EAT) View → Open subviews → Exports
24. aaaddress1 at The Declaration of Hacker (TDOH) Is it true? Nope, Not at all. It will take too much time to search.
25. aaaddress1 at The Declaration of Hacker (TDOH) Wiki
26. aaaddress1 at The Declaration of Hacker (TDOH) Wiki
27. aaaddress1 at The Declaration of Hacker (TDOH) Wiki The head of PE file is DOS header, and that starts with sginature 0x5A4D
28. aaaddress1 at The Declaration of Hacker (TDOH) Wiki That’s why it’s also called DOS-MZ
29. aaaddress1 at The Declaration of Hacker (TDOH) Wiki And (DOS Header + 0x3C) stores the offset of NT Header
30. aaaddress1 at The Declaration of Hacker (TDOH) Wiki This is the real header of PE
31. aaaddress1 at The Declaration of Hacker (TDOH) Wiki (NT Header + 0x028) stores the offset of the first entry function that as known as ‘start’ function.
32. aaaddress1 at The Declaration of Hacker (TDOH) Wiki (NT Header + 0x034) stores the offset of the PE file loaded at where in memory e.g. 0x400000
33. aaaddress1 at The Declaration of Hacker (TDOH) CE Right click → ‘Go to address’ → Input ‘main.exe’ You will find the main.exe loaded at 0x400000 MZ
34. aaaddress1 at The Declaration of Hacker (TDOH) CE 0x0000110b + 0x400000 = 0x40110b That’s the same as the address in IDA
35. aaaddress1 at The Declaration of Hacker (TDOH) If you understand the whole PE structure, you can make a great PE packer :P
36. aaaddress1 at The Declaration of Hacker (TDOH) IMPORT ADDRESS TABLE
37. aaaddress1 at The Declaration of Hacker (TDOH) View → Open subviews → Imports IDA IAT stores all API program calls
38. aaaddress1 at The Declaration of Hacker (TDOH) Double Click & Show the API detail at IAT IDA
39. aaaddress1 at The Declaration of Hacker (TDOH) Strings List
40. aaaddress1 at The Declaration of Hacker (TDOH) View → Open subviews → Strings IDA
41. aaaddress1 at The Declaration of Hacker (TDOH) IDA
42. aaaddress1 at The Declaration of Hacker (TDOH) Assembly: Data
43. aaaddress1 at The Declaration of Hacker (TDOH) C Data Type
44. aaaddress1 at The Declaration of Hacker (TDOH) Program counter
45. aaaddress1 at The Declaration of Hacker (TDOH) Stack Pointer
46. aaaddress1 at The Declaration of Hacker (TDOH) Base Pointer
47. aaaddress1 at The Declaration of Hacker (TDOH) Byte Byte Byte Byte EAX = 4Byte = int = long Register Type
48. aaaddress1 at The Declaration of Hacker (TDOH) Byte Byte Byte Byte AX = 2 Byte = Short Register Type
49. aaaddress1 at The Declaration of Hacker (TDOH) Byte Byte Byte Byte AH = 1 Byte = Char Register Type
50. aaaddress1 at The Declaration of Hacker (TDOH) Byte Byte Byte Byte AL = 1 Byte = Char Register Type
51. aaaddress1 at The Declaration of Hacker (TDOH) Assembly: Opcode
52. aaaddress1 at The Declaration of Hacker (TDOH) Nop (0x90) → Nothing to do.
53. aaaddress1 at The Declaration of Hacker (TDOH) Mov dest,source → dest = source Mov dest, [source] → source = value of dest
54. aaaddress1 at The Declaration of Hacker (TDOH)
55. aaaddress1 at The Declaration of Hacker (TDOH)
56. aaaddress1 at The Declaration of Hacker (TDOH) Add dest,source → dest += source Add dest, [source] → dest += value of source
57. aaaddress1 at The Declaration of Hacker (TDOH) Sub dest, source → dest -= source Sub dest, [source] → dest -= value of source
58. aaaddress1 at The Declaration of Hacker (TDOH) Inc dest → dest ++ Inc [dest] → (value of dest)++
59. aaaddress1 at The Declaration of Hacker (TDOH) Dec dest → dest -- Dec [dest] → (value of dest)--
60. aaaddress1 at The Declaration of Hacker (TDOH) Cmp [source], value //Compare *(long*)source with value Je blockOne // Jump to blockOne if they’re equal Jl blockTwo // Jump to blockTwo if [source] less than value Jg blockThree // Jump to blockThree if [source] greater than value
61. aaaddress1 at The Declaration of Hacker (TDOH) Cmp [source], value //Compare *(long*)source with value Jne blockOne // Jump to blockOne if they’re not equal Jnl blockTwo // Jump to blockTwo if [source] not less than value Jng blockThree // Jump to blockThree if [source] not greater than value
62. aaaddress1 at The Declaration of Hacker (TDOH) Test [source], value //Compare *(long*)source with value Jz blockOne // Jump to blockOne if ([source] - value) is zero Ja blockTwo // Jump to blockTwo if ([source] - value) is above zero Jb blockThree // Jump to blockThree if ([source] - value) is below zero
63. aaaddress1 at The Declaration of Hacker (TDOH) Test v.s. Cmp Using Cmp & Jl/Je/Jg If source & dest are signed number Using Test & Jb/Jz/Ja If source & dest are unsigned
64. aaaddress1 at The Declaration of Hacker (TDOH) Jmp near +0x200 → EIP = EIP + 0x200
65. aaaddress1 at The Declaration of Hacker (TDOH) Jmp long 0x400000 → EIP = 0x400000
66. aaaddress1 at The Declaration of Hacker (TDOH) Ret → EIP = [ESP+0] & pop [ESP+0]
67. aaaddress1 at The Declaration of Hacker (TDOH) Ret 0x0C → pop 0x0C bytes from stack, i.e. ESP += 0x0C 
 → EIP = [ESP+0] & pop [ESP+0]
68. aaaddress1 at The Declaration of Hacker (TDOH) Xor dest, source → mov dest, ‘A’ //0x41 → xor dest, 0x20 //dest is ‘a’(0x61) now
69. aaaddress1 at The Declaration of Hacker (TDOH) Xor dest, source → mov dest, ‘a’ //0x61 → xor dest, 0x20 //dest is ‘A’(0x41) now
70. aaaddress1 at The Declaration of Hacker (TDOH) 0100 0001 ‘A’(0x41) 0x20 0010 0000 Xor ‘a’(0x61) 0110 0001
71. aaaddress1 at The Declaration of Hacker (TDOH) Assembly: Function Call
72. aaaddress1 at The Declaration of Hacker (TDOH)
73. aaaddress1 at The Declaration of Hacker (TDOH)
74. aaaddress1 at The Declaration of Hacker (TDOH)
75. aaaddress1 at The Declaration of Hacker (TDOH)
76. aaaddress1 at The Declaration of Hacker (TDOH)
77. aaaddress1 at The Declaration of Hacker (TDOH) void Func() { int A = 0; Int B = 1; Int C = 2; } [EBP - 4] =0 [EBP - 8] =1 [EBP - C] =2 push EBP mov EBP,ESP sub ESP, LEN
78. aaaddress1 at The Declaration of Hacker (TDOH) void Func() { nFunc(ARG1,ARG2,ARG3…); } push ebb mov ebp,esp . . push arg3 push arg2 push arg1 call nFunc
79. aaaddress1 at The Declaration of Hacker (TDOH)
80. aaaddress1 at The Declaration of Hacker (TDOH)
81. aaaddress1 at The Declaration of Hacker (TDOH)
82. aaaddress1 at The Declaration of Hacker (TDOH)
83. aaaddress1 at The Declaration of Hacker (TDOH) [EBP+0 ] = Pointer to old EBP [EBP+4 ] = Return Address [EBP+8 ] = Parameter 1 [EBP+C] = Parameter 2 [EBP+10]= Parameter 3 …etc
84. aaaddress1 at The Declaration of Hacker (TDOH) Assembly: Calling Convention
85. aaaddress1 at The Declaration of Hacker (TDOH) Stack ESP + 0 ESP + 4 ESP + 8 ESP + C ESP + 10 ESP + 14
86. aaaddress1 at The Declaration of Hacker (TDOH) Stack ESP + 0 Old EBP ESP + 4 ESP + 8 ESP + C ESP + 10 ESP + 14 _______EIP
87. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP + 0 =ESP Old EBP EBP + 4 EBP + 8 EBP + C EBP + 10 EBP + 14 _______EIP
88. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP - 8 =ESP Buffer EBP - 4 Buffer EBP + 0 Old EBP EBP + 4 EBP + 8 EBP + C _______EIP
89. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP - 8 =ESP 1 EBP - 4 Buffer EBP + 0 Buffer EBP + 4 Old EBP EBP + 8 EBP + C _______EIP
90. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP - 8 =ESP return Address EBP - 4 1 EBP + 0 Buffer EBP + 4 Buffer EBP + 8 Old EBP EBP + C _______EIP
91. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP - 8 =ESP return Address EBP - 4 1 EBP + 0 Buffer EBP + 4 Buffer EBP + 8 Old EBP EBP + C
92. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP - 8 =ESP Old EBP EBP - 4 return Address EBP + 0 1 EBP + 4 Buffer EBP + 8 Buffer EBP + C Old EBP _______EIP
93. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP + 0 =ESP Old EBP EBP + 4 return Address EBP + 8 1 EBP + C Buffer EBP + 10 Buffer EBP + 14 Old EBP _______EIP
94. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP + 0 =ESP Old EBP EBP + 4 return Address EBP + 8 1 EBP + C Buffer EBP + 10 Buffer EBP + 14 Old EBP _______EIP
95. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP - 8 =ESP return Address EBP - 4 1 EBP + 0 Buffer EBP + 4 Buffer EBP + 8 Old EBP EBP + C _______EIP
96. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP - 8 =ESP return Address EBP - 4 1 EBP + 0 Buffer EBP + 4 Buffer EBP + 8 Old EBP EBP + C _______EIP
97. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP - 8 =ESP 1 EBP - 4 Buffer EBP + 0 Buffer EBP + 4 Old EBP EBP + 8 EBP + C _______EIP
98. aaaddress1 at The Declaration of Hacker (TDOH) Stack EBP - 4 =ESP Buffer EBP + 0 Buffer EBP + 4 Old EBP EBP + 8 EBP + C EBP + 10 _______EIP
99. aaaddress1 at The Declaration of Hacker (TDOH) x86 Disassembly & Calling Conventions
100. aaaddress1 at The Declaration of Hacker (TDOH) It’s time to talk about each register meanings and their functions used for.
101. aaaddress1 at The Declaration of Hacker (TDOH) I collect the simple parts from wiki, and they’re real useful for reversing. read more: x86 Disassembly/Calling Conventions
102. aaaddress1 at The Declaration of Hacker (TDOH)
103. aaaddress1 at The Declaration of Hacker (TDOH) CDECL
104. aaaddress1 at The Declaration of Hacker (TDOH)
105. aaaddress1 at The Declaration of Hacker (TDOH) STDCALL
106. aaaddress1 at The Declaration of Hacker (TDOH)
107. aaaddress1 at The Declaration of Hacker (TDOH) FASTCALL
108. aaaddress1 at The Declaration of Hacker (TDOH)
109. aaaddress1 at The Declaration of Hacker (TDOH) C++ THISCALL
110. aaaddress1 at The Declaration of Hacker (TDOH) DEBUGGing
111. aaaddress1 at The Declaration of Hacker (TDOH) Debug: Ollydbg
112. aaaddress1 at The Declaration of Hacker (TDOH) Debug: Cheat Engine
113. aaaddress1 at The Declaration of Hacker (TDOH) Debug: IDA Pro
114. aaaddress1 at The Declaration of Hacker (TDOH) Trial: TDOH Hello World
115. aaaddress1 at The Declaration of Hacker (TDOH) Play the game & Find the flag :P
116. aaaddress1 at The Declaration of Hacker (TDOH) Game Time
117. aaaddress1 at The Declaration of Hacker (TDOH)
118. aaaddress1 at The Declaration of Hacker (TDOH) IDA
119. aaaddress1 at The Declaration of Hacker (TDOH) IDA
120. aaaddress1 at The Declaration of Hacker (TDOH) Live Demo IDA, CE, Olly
121. aaaddress1 at The Declaration of Hacker (TDOH) ‘Generate Pseudocode(F5)’ of IDA Pro might lose something important in assembly for accessible reading. It’s important to use debugger and trace opcode of every step. IDA
122. aaaddress1 at The Declaration of Hacker (TDOH) Trial: Lucky Day
123. aaaddress1 at The Declaration of Hacker (TDOH) Game Time
124. aaaddress1 at The Declaration of Hacker (TDOH)
125. aaaddress1 at The Declaration of Hacker (TDOH)
126. aaaddress1 at The Declaration of Hacker (TDOH)
127. aaaddress1 at The Declaration of Hacker (TDOH)
128. aaaddress1 at The Declaration of Hacker (TDOH) TDOH{Debug_is_Fun!}
129. aaaddress1 at The Declaration of Hacker (TDOH)
130. aaaddress1 at The Declaration of Hacker (TDOH) Live Demo IDA, CE, Olly
131. aaaddress1 at The Declaration of Hacker (TDOH) Game Time 清华⽹网络安全技术协会
132. aaaddress1 at The Declaration of Hacker (TDOH)
133. aaaddress1 at The Declaration of Hacker (TDOH) Game Time
134. aaaddress1 at The Declaration of Hacker (TDOH)
135. aaaddress1 at The Declaration of Hacker (TDOH)
136. aaaddress1 at The Declaration of Hacker (TDOH)
137. aaaddress1 at The Declaration of Hacker (TDOH)
138. aaaddress1 at The Declaration of Hacker (TDOH)
139. aaaddress1 at The Declaration of Hacker (TDOH)
140. aaaddress1 at The Declaration of Hacker (TDOH)
141. aaaddress1 at The Declaration of Hacker (TDOH)
142. aaaddress1 at The Declaration of Hacker (TDOH) Live Demo IDA, CE, Olly
143. aaaddress1 at The Declaration of Hacker (TDOH) GAME TIme AIS3 2016 Final Binary 1
144. aaaddress1 at The Declaration of Hacker (TDOH) Game Time
145. aaaddress1 at The Declaration of Hacker (TDOH) Using ‘Strings Window’ to figure out the format string of printf and double click for detail.
146. aaaddress1 at The Declaration of Hacker (TDOH) Click the xref and follow
147. aaaddress1 at The Declaration of Hacker (TDOH)
148. aaaddress1 at The Declaration of Hacker (TDOH) Just check every char of the input is lower case
149. aaaddress1 at The Declaration of Hacker (TDOH)
150. aaaddress1 at The Declaration of Hacker (TDOH) RC4 but a little diffrent. I will take this function into three parts for you understanding well.
151. aaaddress1 at The Declaration of Hacker (TDOH)
152. aaaddress1 at The Declaration of Hacker (TDOH)
153. aaaddress1 at The Declaration of Hacker (TDOH)
154. aaaddress1 at The Declaration of Hacker (TDOH) If the result after RC4 cipher is the same as input, that will be the really key.
155. aaaddress1 at The Declaration of Hacker (TDOH)
156. aaaddress1 at The Declaration of Hacker (TDOH) Live Demo IDA, CE, Olly
157. aaaddress1 at The Declaration of Hacker (TDOH) Game TIme 特訓99
158. aaaddress1 at The Declaration of Hacker (TDOH)
159. aaaddress1 at The Declaration of Hacker (TDOH) I prepare the same one but patched. If you can set bullet count to zero, the game will give you flag.
160. aaaddress1 at The Declaration of Hacker (TDOH) Game Time
161. aaaddress1 at The Declaration of Hacker (TDOH)
162. aaaddress1 at The Declaration of Hacker (TDOH)
163. aaaddress1 at The Declaration of Hacker (TDOH)
164. aaaddress1 at The Declaration of Hacker (TDOH) Live Demo IDA, CE, Olly
165. aaaddress1 at The Declaration of Hacker (TDOH) Game Time CrackMe#1 [UBC] by bRaINbuSY
166. aaaddress1 at The Declaration of Hacker (TDOH) Game Time
167. aaaddress1 at The Declaration of Hacker (TDOH)
168. aaaddress1 at The Declaration of Hacker (TDOH) We don’t care those, that don’t make any effect on the checking Here is used for SEH ExceptionList but it’s not the point
169. aaaddress1 at The Declaration of Hacker (TDOH) We can make it simple like this.
170. aaaddress1 at The Declaration of Hacker (TDOH) We should figure how to get this value ( you can debug and get this without doubt, but it’s import to know how it works for creating a keygen)
171. aaaddress1 at The Declaration of Hacker (TDOH)
172. aaaddress1 at The Declaration of Hacker (TDOH)
173. aaaddress1 at The Declaration of Hacker (TDOH)
174. aaaddress1 at The Declaration of Hacker (TDOH)
175. aaaddress1 at The Declaration of Hacker (TDOH) Live Demo IDA, CE, Olly
176. aaaddress1 at The Declaration of Hacker (TDOH) Q&A aaaddress1@gmail.com