We're given an image file named `A_Real_Space_Hero.jpg`. Because this is forensics, we're dealing with something hidden inside the image.


We can start with checking the file with `exiftool`.

```bash
--- redacted due to brevity ---
Warning : Invalid JUMBF sequence number
```

It looks like there is something strange with this image. Let's look further, and run `binwalk` against the image.

```bash
258102 0x3F036 Zip archive data, at least v2.0 to extract, compressed size: 114, uncompressed size: 124, name: secrets/piece_104.png
258267 0x3F0DB Zip archive data, at least v2.0 to extract, compressed size: 150, uncompressed size: 198, name: secrets/piece_105.png
258468 0x3F1A4 Zip archive data, at least v2.0 to extract, compressed size: 146, uncompressed size: 183, name: secrets/piece_106.png

# redacted due to brevity
```

Okay we've definetly found something. Let's extract the zip archive again using `binwalk`.

```bash
binwalk -e A_Real_Space_Hero.jpg
```

We're now given a directory, conveniently named "secrets", with hundreds of image files hidden within that directory. These files are named `piece_[number].png`, and as the name suggests, they are pieces of a larger image. There's a total of 400 pieces in the directory, and we can assume the image is 200px by 200px (as each piece is 20px by 20px).

```python
from PIL import Image
import os

pieces = [filename for filename in os.listdir("./secrets")]
pieces.sort(key=lambda x: int(x.split("_")[1][:-4]))

first_piece = Image.open(os.path.join("./secrets", pieces[0]))
width, height = first_piece.size

rows = len(pieces) // width
columns = width

assembled_image = Image.new("RGB", (width * columns, height * rows))

for i, filename in enumerate(pieces):
piece = Image.open(os.path.join("./secrets", filename))
x = (i % columns) * width
y = (i // columns) * height
assembled_image.paste(piece, (x, y))

assembled_image.save("final.png")
print("saved")
```

We're now given a QR code, which we can scan to get the flag. I just dragged the image onto CyberChef and got the flag.


```
shctf{s0_l0ng_4nd_th4nks_f0r_4ll_th3_flags}
```

(hey look, it's a reference!)