# 6.4 习题答案

- 一、基础知识篇
 - [1.1 ctf 介绍]

- 二、工具篇
 - [2.1 gdb/peda]
 - [2.2 ollydbg]
 - [2.3 windbg]
 - [2.4 radare2]
 - [2.5 IDA Pro]
 - [2.6 pwntools]

- 三、分类专题篇
 - [3.1 Reverse]
 - [3.2 Crypto]
 - [3.3 Pwn]
 - [3.4 Web]
 - [3.5 Misc]
 - [3.6 Mobile]

- 四、技巧篇

- 五、高级篇

- 六、附录
 - [6.1 更多 Linux 工具](#6.1)
 - [6.2 更多 Windows 工具]
 - [6.3 博客、文章和书籍]
 - [6.4 习题 write-up]

## <span id="6.1">6.1 更多 Linux 工具</span>
#### Strings - strings_crackme
```text
[firmy@Reverse]$ strings -e L strings_crackme
w0wgreat
```

#### Strings - flag_pwnablekr
```text
[firmy@Reverse]$ ./flag_pwnablekr 
I will malloc() and strcpy the flag there. take it.
[firmy@Reverse]$ strings flag_pwnablekr | grep UPX
UPX!
$Info: This file is packed with the UPX executable packer http://upx.sf.net $
$Id: UPX 3.08 Copyright (C) 1996-2011 the UPX Team. All Rights Reserved. $
UPX!
UPX!
[firmy@Reverse]$ upx -d flag_pwnablekr 
                       Ultimate Packer for eXecutables
                          Copyright (C) 1996 - 2017
UPX 3.94        Markus Oberhumer, Laszlo Molnar & John Reiser   May 12th 2017
        File size         Ratio      Format      Name
   --------------------   ------   -----------   -----------
    883745 <-    335288   37.94%   linux/amd64   flag_pwnablekr
Unpacked 1 file.
[firmy@Reverse]$ strings flag_pwnablekr | grep -i upx
UPX...? sounds like a delivery service :)
```

#### xxd - xxd_crackme
```text
[firmy@Reverse]$ xxd -g1 xxd_crackme
......
00001020: 00 00 00 00 67 30 30 64 4a 30 42 21 00 00 00 00  ....g00dJ0B!....
......
```
```text
[firmy@Reverse]$ strings -d xxd_crackme 
......
g00dJ0B!
......
```