BUUCTF:[*CTF2019]otaku

题目来源：https://buuoj.cn/challenges

题目给的zip是伪加密，修改标识符后打开得到如下两文件

其中zip加密，注释有提示，应该是明文加密

 

先看doc，没啥思路，遂百度wp

文档隐藏文字转GBK编码

 脚本

# -*- coding:GBK -*-
f = open('data.txt','w')
s = "Hello everyone, I am Gilbert. Everyone thought that I was killed, but actually I survived. Now that I have no cash with me and I’m trapped in another country. I can't contact Violet now. She must be desperate to see me and I don't want her to cry for me. I need to pay 300 for the train, and 88 for the meal. Cash or battlenet point are both accepted. I don't play the Hearthstone, and I don't even know what is Rastakhan's Rumble."
f.write(s)
f.close()

明文攻击

解压zip得到png和txt

txt没啥用，png是zsteg隐写

flag{vI0l3t_Ev3rg@RdeN}