STORY DRIVEN OSINT CTF

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insane

Emergency Transmission

Briefing

Greetings, Special Agent.

We have an emergency situation, one of the Klumgon pilots was shot down over Ecuador. We received an emergency transmission, but the radio was unable to transmit the last location in full. However, we were able to get a partial transmission from a local cellphone tower. Don’t ask me how, but some friends pulled strings and here we are. It’s up to you to decode the message and find out where the pilot crashed. Once you have the answer, we’ll dispatch a rescue and recovery unit, before the local authorities can get to him. Below you’ll find the emergency call between air traffic control and the vessel. As well as the encrypted message we pulled from the tower.

As always, Special Agent, the contract is yours, if you choose to accept

Materials

9g_9;;bg+l+@/Y"7RodA$;j/_6;KsP91;c%7TrYg9h%HC868Dc$:mij6rZKQ+B_?+<?Ob6+AZ'/7LDLZ85N5f<?Ob3:/je-7RBd87n?QH9iY>!$?C'&EZf[AE?K.FBHUu/Gp%*:BQ##>@WNZ+F*W%[email protected]$KEctr6+Dl+1E+0r2A8u[.+E2U;+D>q8Df?h9EFs0!+DuL7H6?pJD]iS7C`mV6B6eeGD0fW!Fs)'UGp%ESH#mR)7p/5T+AZ-C6;puS<(U7#6;U3B<)Zpc$:IZY7SQ9Q;@6)p6pj[M8Po

Pilot: “Mayday, Mayday, Mayday. This is the Star Vessel Zeta Alpha 9, registration number “KLUMKLOOV” We are under hostile fire, repeat, under hostile fire. Location: Earth’s atmosphere, coordinates approximately …. static…. , over Ecuador. Experiencing critical systems failure and losing altit—”

(Transmission is abruptly cut off with static)

Earth Air Traffic Control (ATC): “Star Vessel Zeta Alpha 9, this is Earth Control. Please respond. We acknowledge your distress call. Squawk 7700. Can you provide your current status?”

(No response, just static)

ATC: “Star Vessel Zeta Alpha 9, if you can hear us, you are cleared for emergency descent. We are alerting all available response teams. Please provide your status update as soon as possible.”

(Continued static indicating a loss of communication)

Answer Instruction

Use the answer to unlock the flagfile, this will reward you with your badge.

Submit your findings in the following format: -0.000000,-00.000000,00

Flagfile

Be advised, the flagfile is an encrypted ZIP. Make sure your OS supports the ZIP format. Ensure the password contains no hidden characters or formatting, paste in Notepad first if the password doesn’t seem to work.

Download Flagfile here

PS: Don’t forget to claim your Coins and XP, by posting your card in the #card-brag channel in Discord.

Official Write-up

Provided here is the official write-up, it does contain the answer. Use this if you’re stuck, or want to verify if you got the answer correct.

Emergency Transmission

A Klumgon pilot has been shot down over Ecuador, and we need to decode an emergency transmission to find their exact coordinates. The challenge involves a multi-step decryption process of intercepted communications.

Available Materials

  1. Radio transmission transcript between the pilot and Air Traffic Control
  2. Encrypted message from a local cell tower
  3. The vessel’s registration number “KLUMKLOOV” (important for decryption)
  4. Base85 encoded message
  5. Final coordinate format requirements

Solution Path

Step 1: Initial Decoding – Base85

The first step is to decode the Base85 encoded message. Base85 (also known as Ascii85) is a form of binary-to-text encoding that’s more efficient than Base64.

Take the provided encoded string:

9g_9;;bg+l+@/Y"7RodA$;j/_6;KsP91;c%7TrYg9h%HC868Dc$:mij6rZKQ+B_?+<?Ob6+AZ'/7LDLZ85N5f<?Ob3:/je-7RBd87n?QH9iY>!$?C'&EZf[AE?K.FBHUu/Gp%*:BQ##>@WNZ+F*W%[email protected]$KEctr6+Dl+1E+0r2A8u[.+E2U;+D>q8Df?h9EFs0!+DuL7H6?pJD]iS7C`mV6B6eeGD0fW!Fs)'UGp%ESH#mR)7p/5T+AZ-C6;puS<(U7#6;U3B<)Zpc$:IZY7SQ9Q;@6)p6pj[M8Po

This needs to be decoded using Base85 decoding.

Step 2: Vigenere Cipher Decryption

After the Base85 decoding, the resulting text needs to be decrypted using a Vigenere cipher:

  • Key: “KLUMKLOOV” (from the pilot’s vessel registration number in the briefing)
  • The Vigenere cipher is a polyalphabetic substitution cipher that uses a keyword to encrypt/decrypt text

Step 3: Coordinate Extraction

After decryption, you’ll get the coordinates in this format:

dash one dot two five one niner four six comma dash seven eight dot three seven zero one six seven comma one niner

Step 4: Format Conversion

Convert the military-style spoken coordinates to numerical format:

  • “dash” → “-“
  • “niner” → “9”
  • “dot” → “.”
  • “comma” → “,”

Final format: -1.251946,-78.370167,19

Required Answer Format

The coordinates must be submitted in this exact format:

-0.000000,-00.000000,00

Key formatting rules:

  • Include negative signs where needed
  • Use exact number of decimal places
  • Include commas between components
  • No spaces
  • Include altitude number

Tips for Solvers

  1. Use reliable Base85 decoding tools
  2. Double-check the Vigenere key spelling (“KLUMKLOOV”)
  3. Pay attention to the military number format conversion
  4. Verify coordinates fall within Ecuador
  5. Follow the exact format requirements

Common Pitfalls to Avoid

  1. Using wrong Vigenere key (watch for spelling)
  2. Incorrect Base85 decoding tool
  3. Missing any decryption steps
  4. Wrong coordinate format
  5. Incorrect conversion of military numbers

Tools Needed

  1. Base85 decoder
  2. Vigenere cipher decoder
  3. Text-to-coordinate converter

Verification Steps

Verify altitude component is included

Confirm Base85 decode was successful

Verify Vigenere decryption produced readable text

Check coordinates fall within Ecuador

Ensure exact formatting matches requirements

Creator(s): Frank Diepmaat