[*CTF2019]otaku

1.题目概述

BUU上少了题目描述

One day,you and your otaku friend went to the comic expo together and he had a car accident right beside you.Before he died,he gave you a USB hard disk which contained this zip.Please find out his last wish.
提示：The txt is GBK encoding.

2.解题过程

010打开

藏着其他的zip，kali分离

binwalk分离文件

寻找docx隐藏内容

爆破无果，去前面那个docx文档里寻找线索

很明显，这个文档隐藏了一些内容

在搜索框里搜索显示/隐藏编辑标记，显示出隐藏的内容

对比发现，隐藏的内容为：

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."

去掉不可见符号

利用记事本的替换功能

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."

然后联想刚刚那个加密压缩包里的last words.txt，猜想是明文攻击，把这段文字改成GBK编码（BUU上漏掉了这一个关键性的提示）

转换为GBK

# -*- coding:GBK -*-
f = open('flag1.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()

打开转换后的GBK文件