HEX ADVENT 2025: Crack the Advent, Conquer the Threat 🐛
WELCOME TO HEX ADVENT 2025, ‘tis the season to Unwrap Your Potential! 🎁
HEX ADVENT 2025 is a Christmas-themed CTF Advent Calendar, designed for women, by women.
What to Expect
- 12 Days, 12 Challenges: A structured schedule to build mastery across different CTF categories.
- Focus Areas:
- Pwn (Binary Exploitation)
- Cryptography
- Reverse Engineering
- Forensics
- OSINT
- Web Exploitation
- Our Mission: To empower women in cybersecurity, create visible role models, and cultivate a robust local talent pool.
| Date | What To Expect? |
|---|---|
| 1 to 12 Dec 2025 | New challenges unlocked at 09:00 SGT daily |
| 1 to 31 Dec 2025 | Challenges open until 31 Dec 2025, 23:59 SGT |
✍🏻➡️ REGISTER TO PLAY NOW
✅➡️ Fill in this Google Form to confirm your eligibility
Event Information & Rules
Please refer to this blog post for the full Event Information and Rules.
Prize Haul
A challenge is considered solved when the correct flag is submitted on CTFd before the final deadline: 31 December 2025, 23:59 SGT.
💰 Cumulative & Shared Prize Pools
| Challenges Solved | Prize Pool |
|---|---|
| 10 | S$400 |
| 11 | S$700 |
| 12 | S$1000 |
The cash prizes are cumulative, and shared equally among all eligible players at each tier.
Example: Players solving 12 challenges stand to receive a share of the S$400, S$700, and S$1000 pools.
Note: If you solve 10/11/12 challenges in total, the write-ups for three specific challenges are mandatory to verify your eligibility for the prize pools.
🎁 Exclusive Swags
| Challenges Solved | Swag |
|---|---|
| ≥ 1 | Exclusive Event T-shirt |
| ≥ 6 | T-shirt, Pin, Key Chain |
| ≥ 10 | All Swags + A share of the three cash prize pools |
Swags are awarded to individuals, and are not shared.
To receive the T-shirt in your preferred size, register on CTFd, and confirm your eligibility by 15 December 2025.
✍🏻 Best Write-Up Prize
We are awarding 3 prizes of S$100 each for the Best Write-Up submissions. Level up your explanation and documentation skills by submitting a write-up for the intermediate pwn, crypto, and reverse engineering challenges!
📋 Write-Up Submission Rules
Write-ups are generally optional, but they are required for prize eligibility in two cases:
- Best Write-Up Prize (Optional): You may optionally submit a write-up for this challenge to compete for the S$100 Best Write-Up Prize.
- For Top Solvers (Mandatory): If you solve 10/11/12 challenges in total, the write-ups for three specific challenges are mandatory to verify your eligibility for the prize pools.
Winning entries will be featured and published on our social media platforms.
📦 Prize Collection
Winners will be notified in January-2026 with the collection details.
❓ Frequently Asked Questions
View our FAQs here
or join the Discord channel for Hex Advent: https://discord.gg/qBEdNFamGs
Credits:
- Challenge Authors: Ada Lum, Ariana Goh, Cherie-Anne Lee, Verity Lim, Wu Yuewei, Yvonne Chua
- Poster Designer: Sarah Tan
- Organising Team: Alicia Ho, Carol Ng, Frances Loy, Joel Wong, Lauren Chua, Sarah Tan
Challenges
Day 1: LAUNCH - HEX ADVENT 2025 is LIVE! Hack Our Christmas Wishlist🎄!
🚨 The Hex Advent Challenge is officially LIVE! Our first challenge, “Christmas Wishlist🎄” by Wu Yuewei, is from the Web Exploitation category. Login or register on our CTFd platform and start playing immediately!
👾 Start hacking: CTFd Platform
✅ Confirm your prize eligibility
Day 2: Merry Osintmas, The Flag is Out There!
Flag 1 captured? Sweet! “Merry Osintmas", written by Ada Lum, is now available. Login or register now and gain access to all the challenges released so far. HEX ADVENT 2025 remains open until 31 December 2025, 23:59 SGT.
👾 Solve Merry Osintmas: CTFd Platform
✅ Confirm your prize eligibility
Day 3: Pwn and Climb the Ranks with Make A Wish!
Challenge the rankings with “Make A Wish”, written by Cherie-Anne Lee. Climb the leaderboard, login or register to play immediately and see how you stack up!
💫 Check scores & “Make A Wish”: CTFd Platform
✅ Confirm your prize eligibility
Day 4: Hex xor bin is Ready for Decryption!
Written by Ariana Goh, today’s challenge, “Hex xor bin” will test your Crypto expertise. Login or register today and access the full set of challenges. Start decrypting!
👾 Tackle Hex xor bin: CTFd Platform
✅ Confirm your prize eligibility
Day 5: Mid-Week Status – Disassemble the Christmas Tree! 🎄
It’s never too late to patch the gap while tackling “Christmas Tree” by Verity Lim. Login or register now and gain access to catch up on all previous challenges 👇🏻
👾 Catch up & play: CTFd Platform
✅ Confirm your prize eligibility
Day 6: Caught You! Querying Flags is Now Spinning! 🕸️
Spider-senses are tingling! Unravel the source code and test your Web Exploitation skills with “Querying Flags” by Ariana Goh. The flag is waiting to be caught, login or register now and start the hunt!
👾 Play now: CTFd Platform
✅ Confirm your prize eligibility
Day 7: Halfway There! Decode “Santa’s Message”!
We’re officially halfway through the challenges in HEX ADVENT 2025! Verity Lim invites you to test your investigative skills with the Forensics puzzle: “Santa’s Message”.
Join the event anytime! We welcome players to register, access all the released challenges so far, and work through them at your own pace.
👾 Detective work starts now: CTFd Platform
✅ Confirm your prize eligibility
Day 8: Level Up with HEX ADVENT 2025’s First Intermediate Challenge – Ho Ho Heap!
Time to see how you stack up, our first Intermediate challenge is here! Test your skills with the Pwn challenge: “Ho Ho Heap!”, written by Cherie-Anne Lee.
Log in or register now to access all challenges released so far and tackle this new difficulty tier!
👾 Go to “Ho Ho Heap!”: CTFd Platform
✅ Confirm your prize eligibility
📝 Submit your write-up to compete for the Best Write-Up Prize!
(Note: Mandatory write-ups are required for players who solved 10/11/12 challenges. Eligibility will be verified before prizes are disbursed.)