Problem

Someone sent me a file with white and black rectangles. I don’t know how to read it. Can you help me?

Attachment: https://ctf.internetwache.org/files/misc60.zip

Solved by 269 teams

Solution

We get a text file with a lot of base64, we dump it to a file:

cat README.txt | base64 -d > out

and see what’s inside:

There were 24 ASCII QR Codes in the file, no python magic here, just a quick scan with a mobile app and we get the message letter-by-letter: Flagis:IW{QR_C0DES_RUL3}.

Flag: IW{QR_C0DES_RUL3}