CyberGame.sk 2025

All challenges are archived (if possible) in their respective directories, you should find all files that were given for the challenge. Many of them can be run/solved locally. Files related to solving the challenge are always in Solution/ folder, avoid it if you don't want spoilers.

I tend to over-do and over-complicate things - you've been warned. If you have a better solution, send me a Pull Request 🙂.

Dependencies

When you see commands like r.emit or r.b64 or other r.<something> in some of the write-ups, that is Binary Refinery, basically CyberChef in a command-line, but better, lol. If you do not use it yet, you should.

Some of the crypto challenges use SageMath, you can find follow the Sage Installation Guide.

Python virtual environment

A lot of the solutions use Python and various libraries, if you want to play with the scripts, it is best to create a virtual environment and install the dependencies:

python3.13 -m venv venv # may work with a different version, 3.13 is what I used
source venv/bin/activate
pip install -U pip wheel
pip install -r requirements.txt

Challenges (Table of Contents)

Some write-ups are split-up per sub-challenge, some are not - depends on their length and how related they are.

Cryptography

[☆☆☆] Advanced Decryption Standard

• Codebook (1 pts)
• Blockchain (1 pts)
• easy like counting up to three (1 pts)

[★☆☆] Adversary

• Almost Classic (3 pts)
• 3AES (3 pts)
• Key exchange (9 pts)

[★☆☆] Ransomware

• Recovery 1 (3 pts)
• Recovery 2 (3 pts)
• Recovery 3 (9 pts)

[★★☆] Short Crypto Tales

• MorizOtis (3 pts)
• Suibom (3 pts)
• SecretFunction^2 (18 pts)

[★★★] Elliptic

• Simple curve definition (9 pts)
• How to break so many bits? (9 pts)
• 3 Curves and mysterious story (27 pts)

Malware Analysis and Reverse Engineering

[☆☆☆] SanityChecker

• Sleepy python (1 pts)
• Bash dropper (1 pts)
• Password protected (1 pts)

[★☆☆] ConnectionChecker

• Tool (3 pts)
• Lies (3 pts)
• Executer (9 pts)

[★★☆] The Chronicles of Greg

• SystemUpdate incident report (6 pts)
• The Blob Whisperer (6 pts)
• The Shared Object Prophecy (18 pts)

[★★★] JAILE3

• MathEmulator (9 pts)
• Loader (27 pts)

Forensics

[☆☆☆] First Contact

• Hard choices (1 pts)
• In competition with jellyfish (1 pts)
• So long, but wait, we’re still playing! (1 pts)
• Still fighting (1 pts)
• Between 15 and 17 (1 pts)
• A Day in the Strife (1 pts)
• Independence day (1 pts)
• Or hack their mainframe... (1 pts)

[★☆☆] Bastion

• So much just from logs (3 pts)
• Inspect the file system (3 pts)
• Clean bastion (3 pts)
• Feel free to dig in (3 pts)
• The backdoor culprit (9 pts)

[★☆☆] The Chronicles of Greg 2

• Frustrating compression (3 pts)
• You need stronger glasses (6 pts)

[★★☆] Eugene’s FATigue

• FATigue (6 pts)
• Is that it? (6 pts)
• Was that the only file? (6 pts)
• It tastes like a poem (6 pts)
• Wrapping it up (18 pts)

OSINT

[★☆☆] The digital trail

• The tip (3 pts)
• The evidence (3 pts)
• The digital footprint (3 pts)
• The private channel (3 pts)
• The escape plan (9 pts)

[★★★] Suspect tracking

• Identification (9 pts)
• Localization (9 pts)
• Golden Hour (27 pts)

Process and Governance

[★☆☆] Reading the dusty books

• Handling (3 pts)
• Colors of the rainbow (6 pts)

Web Exploitation and Binary Exploitation

[★★☆] Equestria

• Door To The Stable (6 pts)
• Shadow Realm (6 pts)
• The Dark Ruler (6 pts)
• Final Curse (18 pts)

[★★☆] JAILE

• Calculator (6 pts)
• User (6 pts)
• Final Escape (18 pts)

[★★☆] JAILE2

• Calculator v2 (6 pts)
• The Tasty Bun (6 pts)
• dictFS (6 pts)
• Blazing-fast, memory-safe interpreter (18 pts)

[★★☆] ByteBusters

• Terminal Magic (6 pts)
• Secure Shell (6 pts)
• Memory Phantoms (6 pts)
• Binary Sabotage (18 pts)

[★★★] Meme History Blog

• Scratching the surface (9 pts)
• Digging Deep (27 pts)