diff --git a/README.md b/README.md
index 939e494..fe7ec24 100644
--- a/README.md
+++ b/README.md
@@ -83,6 +83,7 @@
     - [6.2.1 re XHPCTF2017 dont_panic](doc/6.2.1_re_xhpctf2017_dont_panic.md)
     - [6.2.2 re ECTF2016 tayy](doc/6.2.2_re_ectf2016_tayy.md)
     - [6.2.3 re Codegate2017 angrybird](doc/6.2.3_re_codegate2017_angrybird.md)
+    - [6.2.4 re CSAWCTF2015 wyvern](doc/6.2.4_re_csawctf2015_wyvern.md)
 
 - [七、附录](doc/7_appendix.md)
   - [7.1 更多 Linux 工具](doc/7.1_Linuxtools.md)
diff --git a/SUMMARY.md b/SUMMARY.md
index aa8de36..4d4c08b 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -82,6 +82,7 @@ GitHub 地址：https://github.com/firmianay/CTF-All-In-One
     * [6.2.1 re XHPCTF2017 dont_panic](doc/6.2.1_re_xhpctf2017_dont_panic.md)
     * [6.2.2 re ECTF2016 tayy](doc/6.2.2_re_ectf2016_tayy.md)
     * [6.2.3 re Codegate2017 angrybird](doc/6.2.3_re_codegate2017_angrybird.md)
+    * [6.2.4 re CSAWCTF2015 wyvern](doc/6.2.4_re_csawctf2015_wyvern.md)
 * [七、附录](doc/7_appendix.md)
   * [7.1 更多 Linux 工具](doc/7.1_Linuxtools.md)
   * [7.2 更多 Windows 工具](doc/7.2_wintools.md)
diff --git a/doc/5.2_pin.md b/doc/5.2_pin.md
index 6d2371c..cdafb55 100644
--- a/doc/5.2_pin.md
+++ b/doc/5.2_pin.md
@@ -422,7 +422,6 @@ Count 152786
 #### 练习
 - [**RE** - picoCTF 2014 - Baleful](../src/Reverse/5.2_baleful)
 - [**RE** - Hack You 2014 - reverse - 400](../src/Reverse/5.2_reverse_400)
-- [**RE** - CSAW CTF 2015 - wyvern - 500](../src/Reverse/5.2_wyvern_500)
 - [**RE** - th3jackers CTF 2015 - rev100 - 100](../src/Reverse/5.2_th3jackers_100)
 
 
diff --git a/doc/5.3_angr.md b/doc/5.3_angr.md
index 8dc7971..a1a0b42 100644
--- a/doc/5.3_angr.md
+++ b/doc/5.3_angr.md
@@ -263,6 +263,7 @@ Nice!
 
 
 ## 参考资料
+- [angr.io](http://angr.io/)
 - [docs.angr.io](https://docs.angr.io/)
 - [angr API documentation](http://angr.io/api-doc/)
 - [The Art of War:Offensive Techniques in Binary Analysis](https://www.cs.ucsb.edu/~vigna/publications/2016_SP_angrSoK.pdf)
diff --git a/doc/6.1.3_pwn_xdctf2015_pwn200.md b/doc/6.1.3_pwn_xdctf2015_pwn200.md
index 767de48..2820e16 100644
--- a/doc/6.1.3_pwn_xdctf2015_pwn200.md
+++ b/doc/6.1.3_pwn_xdctf2015_pwn200.md
@@ -355,8 +355,8 @@ typedef struct
   Elf64_Sxword  r_addend;       /* Addend */
 } Elf64_Rela;
 ```
-32 位程序使用 REL，而 64 位程序使用 RE
-LA。
+32 位程序使用 REL，而 64 位程序使用 RELA。
+
 下面的宏描述了 r_info 是怎样被解析和插入的：
 ```C
 /* How to extract and insert information held in the r_info field.  */
diff --git a/doc/6.2.4_re_csawctf2015_wyvern.md b/doc/6.2.4_re_csawctf2015_wyvern.md
new file mode 100644
index 0000000..ca11599
--- /dev/null
+++ b/doc/6.2.4_re_csawctf2015_wyvern.md
@@ -0,0 +1,14 @@
+# 6.2.4 re CSAWCTF2015 wyvern
+
+- [题目解析](#题目解析)
+- [参考资料](#参考资料)
+
+
+## 题目解析
+```
+$ file wyvern 
+wyvern: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.24, BuildID[sha1]=45f9b5b50d013fe43405dc5c7fe651c91a7a7ee8, not stripped
+```
+
+
+## 参考资料
diff --git a/doc/6_writeup.md b/doc/6_writeup.md
index 10524bf..d21c948 100644
--- a/doc/6_writeup.md
+++ b/doc/6_writeup.md
@@ -12,3 +12,4 @@
   - [6.2.1 re XHPCTF2017 dont_panic](6.2.1_re_xhpctf2017_dont_panic.md)
   - [6.2.2 re ECTF2016 tayy](6.2.2_re_ectf2016_tayy.md)
   - [6.2.3 re Codegate2017 angrybird](6.2.3_re_codegate2017_angrybird.md)
+  - [6.2.4 re CSAWCTF2015 wyvern](6.2.4_re_csawctf2015_wyvern.md)
diff --git a/doc/7.4_writeup.md b/doc/7.4_writeup.md
index 4aca207..7ee9ce7 100644
--- a/doc/7.4_writeup.md
+++ b/doc/7.4_writeup.md
@@ -1,72 +1,15 @@
 # 7.4 习题答案
 
-- [一、基础知识篇]()
-  - [1.3 Linux 基础]()
-  - [1.4 Web 安全基础]()
-  - [1.5 逆向工程基础]()
-    - [1.5.1 C 语言基础]()
-    - [1.5.2 x86/x64/ARM 汇编基础]()
-    - [1.5.3 Linux ELF]()
-    - [1.5.4 Windows PE]()
-    - [1.5.5 静态链接]()
-    - [1.5.6 动态链接]()
-    - [1.5.7 内存管理]()
-    - [1.5.8 glibc malloc]()
-  - [1.6 密码学基础]()
-  - [1.7 Android 安全基础]()
-- [二、工具篇]()
-  - [2.1 VM]()
-  - [2.1 gdb/peda]()
-  - [2.2 ollydbg]()
-  - [2.3 windbg]()
-  - [2.4 radare2]()
-  - [2.5 IDA Pro]()
-  - [2.6 pwntools]()
-  - [2.8 zio]()
-  - [2.9 metasploit]()
-  - [2.10 binwalk]()
-  - [2.11 Burp Suite]()
-- [三、分类专题篇]()
-  - [3.1 Reverse]()
-  - [3.2 Crypto]()
-  - [3.3 Pwn]()
-    - [3.3.1 格式化字符串漏洞](#331-格式化字符串漏洞)
-    - [3.3.2 整数溢出]()
-    - [3.3.3 栈溢出]()
-    - [3.3.4 堆溢出]()
-  - [3.4 Web]()
-  - [3.5 Misc]()
-  - [3.6 Mobile]()
-- [四、技巧篇]()
-  - [4.1 AWD模式]()
-  - [4.2 Linux 命令行技巧]()
-  - [4.3 GCC 堆栈保护技术]()
-  - [4.4 使用 DynELF 泄露函数地址]()
-- [五、高级篇]()
-  - [5.1 Fuzz 测试]()
-  - [5.2 Pin 动态二进制插桩](#52-Pin-动态二进制插桩)
-  - [5.3 angr 二进制自动化分析]()
-  - [5.4 反调试技术]()
-  - [5.5 符号执行]()
-  - [5.6 LLVM]()
-- [六、附录]()
-  - [6.1 更多 Linux 工具](#61-更多-linux-工具)
-  - [6.2 更多 Windows 工具]()
-
 
 ## 3.3.1 格式化字符串漏洞
 #### **pwn** - UIUCTF 2017 - goodluck - 200
 
-#### **Pwn** - NJCTF 2017 - pingme - 200
-
 
 ## 5.2 Pin 动态二进制插桩
 #### **RE** - picoCTF 2014 - Baleful
 
 #### **RE** - Hack You 2014 - reverse - 400
 
-#### **RE** - CSAW CTF 2015 - wyvern - 500
-
 #### **RE** - th3jackers CTF 2015 - rev100 - 100
 
 
diff --git a/src/Reverse/5.2_wyvern_500 b/src/writeup/6.2.4_re_csawctf2015_wyvern/wyvern
similarity index 100%
rename from src/Reverse/5.2_wyvern_500
rename to src/writeup/6.2.4_re_csawctf2015_wyvern/wyvern