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Lag'n'Crash CTF: Tedious? Or is it?

March 14, 2021

Challenge Overview

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This challenge is under the Misc category.

My friend pranked me and hide my secret in one these!

A file named tedious.zip is attached. You can download it here.

Solution

Extracting the contents of tedious.zip, we get a file called tedious. This is another zip file that contains a QR directory. Within the QR directory is 4255 other files.

By sorting the files by size, we can find the odd one out:

1337.zip is the odd one out and has the smallest size

Extracting it, we realise that it is a png file containing a QR code. By scanning the QR code, we get the flag: LNC{IS_THlS_TH3_R3AL_0N3?}:

QR code displayed by 1337.zip


Written by Joel Tio who develops anything he finds interesting and tries to fit math into them. Check out the home page or his GitHub!

© 2021, Joel Tio