Rating:

We are given a video file in (.mkv) format, was it just a quick-heal advertisement or not???
You can hear a beeping sound with audio running besides it. Also, you can see some part
of QR flashing in between different frames of video.

Extract all these frames and layer it up, it will create a QR, that will get you to half of the
solution.

Now about the beeping sound, you can’t hear it properly as the ad running keeps blocking
a few beats.

Also I assumed that it must be Morse code so I started filtering different frequencies and
after some guesses and observation, I got 500Hz as the correct frequency for that beeping
audio.

Lastly, decoding that audio using morse I got the final Flag.

```FLAG: VishwaCTF{S3cur1ty_S1mpl1f13d_5NJ0Y_C0UP0NS}```

Original writeup (https://github.com/CBC-MIT/CTF-Writeups/tree/main/VishwaCTF2k23/Quick%20Heal).