# space-dust

First of all, I observed a `==` at the end of the content of the file. Immediated I decoded it from base64 and stored in other file. And the file size is a bit suspicious so I observed its hexdump. It contains a PNG header. So, I renamed the image image into decoded.png. Then i opened the image it has the flag in it.

```bash
mj0ln1r@Linux:~/space-dust$ cat message_from_tom.txt | base64 -d >> decoded
mj0ln1r@Linux:~/space-dust$
mj0ln1r@Linux:~/space-dust$ xxd decode | head
00000000: 8950 4e47 0d0a 1a0a 0000 000d 4948 4452 .PNG........IHDR
00000010: 0000 0a00 0000 05a0 0806 0000 0092 001a ................
00000020: df00 0000 0173 5247 4200 aece 1ce9 0000 .....sRGB.......
00000030: 0004 6741 4d41 0000 b18f 0bfc 6105 0000 ..gAMA......a...
00000040: 0009 7048 5973 0000 0ec3 0000 0ec3 01c7 ..pHYs..........
00000050: 6fa8 6400 00ff a549 4441 5478 5ee4 fd67 o.d....IDATx^..g
00000060: 776c 3b92 a609 1a35 e9d4 fae8 2b43 6556 wl;....5....+CeV
00000070: 5677 4fcf 879e 5933 ffad fe5d d7a8 55d5 VwO...Y3...]..U.
00000080: 5599 1915 1157 9c7b 34b5 763a f5bc cf6b U....W.{4.v:...k

mj0ln1r@Linux:~/space-dust$ mv decoded decoded.png
```

The decoded image is decoded.png .

> `Flag : jctf{th1s_1s_n0t_a_game}`

## [Original Writeup](https://themj0ln1r.github.io/posts/jerseyctf23)