Rating:
Description: One of the admins is an undercover agent. she sent a mysterious file in our group just before deleting her number. Can you help us to decipher what this file is about!
The challenge gives us a GIF file. At first glance, this doesn't look like much. But upon closer inspection, we can actually see that each frame corresponds to the one before. Every 6 frames make a row. My initial idea was to use stegsolve's frame browser and extract every frame, then putting them all together on MS paint. But as I got to frame 50, I noticed that the last frame was much bigger in size and dimensions because it actually holds the combined frames. I didn't have to do all that hard work.
I got this dot image, but I didn't know what it first. So I reverse google imaged to see what I can learn about it. Google tells that it is a DotCode. And so, using an online DotCode decoder, I got the flag.
