Welcome to The Unsolvable CTF


If Sherlock Holmes or Miss Marple came to life today, what would they be? A hacker, a journalist, a police officer or a private investigator? With the power of the Internet and at the comfort of their home, they would have opted for digital sleuthing/e-sleuthing/osinting. Well, that’s the thing about detectives, irrespective of times, politics and the changing world, without prejudices, they do what they do; that’s solving cases that are challenging.

Yes, you heard that right, it’s The Unsolvable CTF! Don’t be disappointed. If something ever existed, it cannot completely cease to exist. Finding anything and everything should be your goal. If not, then why are you even here?

The Unsolvable CTFs are solvable, but they are difficult nuts to crack. Why should it be difficult? Tell a single thing that’s simple in the world. You can write an encyclopedia on Mitochondria, but call it simple? Complexity is the key and chaos is constant. The human lives, the environment around them, and the whole system are complicated.

In The Unsolvable CTF, every challenge is called a Case, and there’s no one to command you or order you, and you are the protagonist, call yourself whatever you want, but I’ll be the string-puller. You’ll get the cases irregularly. In a month, you can get three cases or none. Sometimes, it could be two cases a week or ten if you can, or none! Why? Do you think I can control the chaos? Or can you?

So what’s the deadline to solve the cases? No deadlines. Your lifetime is the deadline. The cases will be there. When you think the case is solved, you just write a short report and mail it to [email protected] {PGP} with the case number in the subject. I’ll read every email, I’ll only reply to you if you have solved the case. And remember, no brute forcing, no clues nor easter eggs will EVER be on the site, it’s just text or sometimes links that provide you with information, that’s that. Nonetheless, there are a lot of places to hide things on the Internet and the world.

Why The Unsolvable CTF is different

In traditional CTFs, most of you have done something like converting a string of Base64 characters into comprehensible text, it’s all fun, no comments on that. But take a step back and try to think practically. Which killer in the history of humankind left a clue in Base64 encoded secret message? Well, I know what you are thinking, The Zodiac Killer. I’ll talk about it in a bit. But in short, Zodiac’s case itself is an example of how complicated human minds can be and the coded messages were self-creation with some influences that gave a really hard time for investigators to make progress, because it was a mind game rather than cheesy little tools that could decode anything and everything.

Let me remind you, most of OSINT is passive recon. That means you have to give more importance to your mind when collecting & collating data, rather than using tools. And by this time(if you are experienced), most of you can visually identify how a Base64 string looks or how the Caesar cipher looks, but do you know about a dialect which is only spoken in North-Eastern India? Or a dish that’s only available in a small restaurant in West Germany.

You might be good at analyzing an image, but hold on, you are not the only one, there are millions. Any OSINTer can tell you what to look for in an image or a video; look for the street signs, look for the insignia, flag, type of buildings, landscape and so on. So what makes you special? The answer is BROADER KNOWLEDGE.

Knowledge about particular things makes you a better investigator. So where can you get all this knowledge? Through the data available that’s open, the Internet, books, movies, travel, objects, folklore and many more. And everyone cannot know everything, but something, over learn or under learn the things that are necessary, because remember you are the protagonist. So keep an open mind about solving the cases. The world is your playground and I’m not going to tell you to catch extraterrestrials on a fictional island. Don’t worry, I’m not that much of a spoilsport. I’ll try to add geolocation challenges in between. As aforementioned, the world is your playground.


Well, all the unsolved cases in the world are my motivation, including your Zodiac Killer! Creating a CTF which truly serves the purpose of passive recon, the true spirit of investigation and human psychology is the biggest motivation. There’s endless information around you and you are just here to navigate through it. If your collection is collated coherently, you’ll be the owner of the crown.

In real life, unsolved cases later turn into mysteries and mysteries become legends and legends give rise to conspiracy theories depending on the culture. But the cases still remain UNSOLVED.

Join our Discord server to discover and discuss about cases - Osint For All Discord and also subscribe to our YouTube channel for OSINT related videos - Osint For All YouTube

This CTF is not intended for a dopamine rush but sleepless nights! 😈

Case-1: Sarah

On October 24 2007, Sarah Gray, a Linguistics and Philosophy student from MIT disappears mysteriously. Her last email was sent to her friend. The subject said, “Hard to say…”, the body said, “I can’t say much right now, I can’t say what happened, I’m being watched, I’m going somewhere, where no one can find me, but I’ll be here somewhere. If you ever find me, say those words and I’ll know” and two PNG files were attached to the email.
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Case-2: Stampede

String Puller: Hello my lovely digital sleuths, our “Machine” is pointing us towards certain incidents from the past while performing a data analysis on a state sponsored cabal. So far we are not able to understand why it’s giving us these results. We tried to look for discrepancies or errors within our system, but surprisingly everything’s in the place and the information is relevant. So these results from the “Machine” should mean something, can you crack this?
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