[HV22.07] St. Nicholas’s animation
Santa has found a weird device called an “Oxocard Blockly”, which seems to display a sequence of images. He believes it has got something to do with a QR code, but it doesn’t seem complete…
You can’t fly to the north pole, so Santa sent you a video of the device in action.
The elves are having a karaoke and left with in a hurry while singing into their micro. This means that they aren’t there to help him, so now is your chance to make a good impression and find the flag!
Solution
We got a video with a tool which seems to be capable of showing 8x8 pixels. It blinks and shows different images. This is the video:
Starting at ~4s it shows a pattern, where it starts top left, then top right, bottom left and finally bottom right.
After that, it shows something like a QR position marker followed by three seemingly random pixel patterns before returning to animated things.
My first intention was to head over to QRazyBox, but unfortunately, this only supports QR codes starting from 21x21 px and not Micro QR, what we are looking at most probably.
Micro QR has the timing information laid out around the top and left edge (assuming standard orientation, where the position marker is at top left). Using this knowledge, I simply used QRazyBox by chosing a random empty area to copy the pixels from the video. Others have done that using a graphics program of their choice by painting individual pixels.
I then used my phone to scan the QR code, but it’s also completely possible to solve it using a micro qr code reader which can be found online.
The flag was HV22{b0f}