Tags: excel bruteforce archive 


# Full WriteUp

Full Writeup on our website: [http://www.aperikube.fr/docs/tjctf_2018/gridparser](http://www.aperikube.fr/docs/tjctf_2018/gridparser)


In this task the author gaves us an Excel file. As all Office file, it’s possible to unzip them. With a quick look, we notice a PNG file in decompressed data.

This PNG is not displayed in the Excel file. Then, *binwalk* extract a little encrypted zip from the PNG file.

Finally, I used *fcrackzip* to bruteforce the password (secret key = *px*).

Original writeup (http://www.aperikube.fr/docs/tjctf_2018/gridparser/).