# PicoCTF - Matryoshka doll
###### tags: `PicoCTF` `CTF` `Misc`
Challenge: [](https://play.picoctf.org/practice/challenge/129?category=4&page=1)

## Exploit - `rar` in `rar`
1. Hint
The hint said:
> Wait, you can hide files inside files? But how do you find them?

So...I tried `stegsolve`, `HxD`, `exiftool`, `string dolls.jpg | grep "{"`, `$ zsteg dolls.jpg` ... All these are in vain
2. <font color="FF0000">通靈</font>: Changed the extension to `.rar`
And it can be uncompressed

3. Repeat until find `flag.txt`...