Beatles Stenography Challenge Solution!

Kamran Saifullah
4 min readJun 11, 2019

Just completed solving the beatles challenge and i must say that this challenge gave me a headache and after i solved this challenge. I laughed on myself.

Let’s dive into solving this challenge.

On doing unzip we are provided with the secret message for Paul!. On checking the message seems to be encrypted.

This encryption is ROT13. Going onto rot13.com for it’s decryption!

So this says that the passphrase is of 4 characters! we need to fcrack the zip file in order to get more closer towards our flag. Guessing this password is an art and this took almost most of the time, including myself and the people who asked me for help in solving this challenge. The password is very simple ;)

Let’s try fcrackzip in order to crack the zip file.

Well no luck so far. “Do you know that password is way more simple! Think Clever!”. Let’s try again using the same tool.

Ohkay! fine. On using the possible password combinations we are presented with the BAND.JPG image but it is invalid compressed and there is no way to get this file corrected.

It’s quite simple that password is something else.

HAHA! even after doing some brain storming i thought with going “BAND” 4 characters and by this the fcrackzip will only check for 4 characters and look what was the password! HAHA! this was given to us in the encrypted text message even.

No issues! already wasted a lot of time finding the correct password! let’s move ahead unzip BAND.zip and now we have the correct BAND.jpg file.

Let’s open this BAND.JPG file!

I tried playing with this image a lot. Almost spend 3–4 hours reading and trying to figure out how this image text can be converted into a flag but to be honest i wasn’t successful.

Will come back to this image. But let’s try to figure out some strings of this image file.

We have found base64 encoded text and it’s very simple to decode!

Well! we have been diverted! and fooled! we needed to be more specific and should look for the clues. Let’s try steghide on this image file.

This confirms that there is something within this file but what is the password?

Well the answer is that image containing the text. “THEBEATLES” is the password :P

WOW! we got the file. Let’s check what file is it?

It’s an executable file. I don’t like its name so renaming it and setting the executable permission in order to run it properly :))

Now it’s time to run the program.

Well i used to solve that math using python as i am bad in mathematics :P you can do them manually too ;) now we are again presented with the base64 code. All we need is to decode it :)) let’s move this text into the file and run base64 — decode on it :))

Sorry my friend! this challenge was no doubt a tricky one although loved this challenge ❤

I hope you liked the walkthrough!

Don’t forget to appreciate!

Thanks for reading!

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Kamran Saifullah

Malware/RE/Firmware Analysis, App Sec/Off Sec, VAPT, Phishing Simulations/SE | Risk Management, IS Governance, Audits, ISO 27001 LI