Challenge
HV19.07 Santa Rider
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1 |
Santa is prototyping a new gadget for his sledge. Unfortunately it still has some glitches, but look for yourself. |
Resources:
For easy download, get it here: HV19-SantaRider.zip
Solution
We watch the provided video and notice that about half way through the LEDs light up in an interesting order. There are 8 total LEDs and multiple LEDs light up at once so we think that this may be hidden binary messages that decode to ASCII. As the video moves very fast its necessary to inspect each frame individually. We can do this by extracting each frame using a tool like FFmpeg but in this case it was faster to simply use a video editor like MPC-HC which allows you to navigate the video frame by frame.
It is very cool to note that because the video is stationary and position of LEDs do not move, one could use a computer vision library like OpenCV to extract the hidden binary.
We get the following binary:
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 |
01001000 01010110 00110001 00111001 01111011 00110001 01101101 01011111 01100001 01101100 01110011 00110000 01011111 01110111 00110000 01110010 01101011 00110001 01101110 01100111 01011111 00110000 01101110 01011111 01100001 01011111 01110010 00110011 01101101 00110000 01110100 00110011 01011111 01100011 00110000 01101110 01110100 01110010 00110000 01101100 01111101 |
We convert this binary to ASCII and get our final flag!
Flag: HV19{1m_als0_w0rk1ng_0n_a_r3m0t3_c0ntr0l}
Bonus
This challenge also contained the solution to HV19.H2 Hidden Two
