Category: CTF


30 Sep 2025

TISC 2025

TISC 2025 Write-ups

This year, I managed to win TISC again šŸŽ‰


30 Sep 2025

TISC 2025, Rev, ARM Pwn

HWisntThatHardv2

Last year many brave agents showed the world what they could do against PALINDROME’s custom TPM chips. Their actions sent chills down the spines of all those who seek to do us harm. This year, we managed to exfiltrate an entire STM32-based system and its firmware from within SPECTRE. You...


30 Sep 2025

TISC 2025, PHP Deserialization

VirusVault

Welcome to the VirusVault, the most secure way to store dangerous viruses. Surely nothing can go wrong storing them this way! http://chals.tisc25.ctf.sg:26182 Attached files: virus_vault.zip Finally, a web challenge with source! This is a pretty straightforward PHP challenge and a refreshing change of pace from the Cloud challenge. The PHP...


30 Sep 2025

TISC 2025, PDF Injection, Cloud

Santa ClAWS

This seemingly innocent site may be hiding something deeper — a covert cloud operations backend. Scratch beneath the surface. Unravel the yarn of lies. Every cat may hold a clue. http://santa-claws.chals.tisc25.ctf.sg After completing Level 6, players are given the option to pick between a Web-oriented route and a Rev-oriented route...


30 Sep 2025

TISC 2025, Web

Passkey

This service is open for anyone to sign up as a user. All you need is a unique username of your choosing, and passkey. Go toĀ https://passkey.chals.tisc25.ctf.sgĀ to begin. This is a blackbox web challenge involving passkeys. Passkeys are a pretty new authentication method. They replace traditional passwords, using biometrics (e.g. Windows...


30 Sep 2025

TISC 2025, Rev

SYNTRA

Your task is to investigate the SYNTRA and see if you can find any leads. http://chals.tisc25.ctf.sg:57190/ Attached files: syntra-server The website is designed to simulate a radio, with various dials and knobs. Let’s look at the provided server binary to figure out what it does. Opening it in IDA, we...


30 Sep 2025

TISC 2025, LLM

Spectre Memory

🚨 ALERT: A mutated AI known as ā€œSpectreLLMā€ has started hallucinating strange signatures. Your task is to identify and neutralise its embedded payload before its spread. http://chals.tisc25.ctf.sg:35189 Another LLM challenge! We are given a web platform where we can submit text input and image input to the LLM. Direct requests...


30 Sep 2025

TISC 2025, Misc

Rotary Precision

We’ve recovered a file from an SD card. It seems important, can you find the hidden content? Attached: rotary-precision.txt In this challenge, we are given a G-Code file. G-Code is a programming language that contains instructions for CNC machines like 3D printers. We can view the model online using NC...


30 Sep 2025

TISC 2025, LLM

The Spectrecular Bot

Just before the rise of SPECTRE, our agents uncovered a few rogue instances of a bot running at http://chals.tisc25.ctf.sg:38163, http://chals.tisc25.ctf.sg:38164 and http://chals.tisc25.ctf.sg:38165. These instances were found to be running the identical services of the bot. Your mission is to analyse this bot’s code, uncover the hidden paths, and trace its...


30 Sep 2025

TISC 2025, v8 pwn, n-day

SpectreChrome

This is a V8 n-day challenge. It was intended for the player to write the whole exploit chain themselves. Unfortunately, by the time TISC rolled around, the PoC for the original vulnerability had been made public. Thus, the challenge was a lot easier than intended. We are given a patch...


30 Sep 2025

TISC 2025, PHP Request Smuggling, n-day, Java deserialization, Spring AOP

Ash Twin Project

This is a 3-part challenge that requires chaining of exploits from each part to get to the final flag. Part 1 is a typical PHP/Redis web challenge. Part 2 is an n-day challenge on a GeoServer web server. Part 3 is a novel Java deserialization gadget chain exploit. The challenge...


30 Sep 2025

TISC 2025, CSS Injection, Rev

Countle Secured Storage

Deep within Mount Countle, thousands of expert gophers have constructed what is believed to be an impenetrable vault for SPECTRE’s most classified secrets. Recent intel has revealed blueprints for an adjacent ā€œadmin_botā€ service, but the inner workings of ā€œCountle Secured Storageā€ remains shrouded in mystery. http://chals.tisc25.ctf.sg:23196 Attached files: countle-secured-storage.zip This...


30 Sep 2025

TISC 2025, OSINT

Target Reference Point

One of our U2 spy planes spotted Spectre units around the area surrounding these lakes. However we lost location metadata while collecting huge amounts of imagery. Can you help us find the name of the lake marked by the target reference point ā€˜+’ symbol? https://satellites.pro/ might be useful to compare...


01 Oct 2024

rev, pwn, hardware

TISC'24 Writeups #3

This is the final part of my TISC write-ups, detailing my solutions to level 10-12. Level 10: Diffuse (Misc) Level 11: Sandboxed Notes App (Pwn) Level 12: Revenge of the Dragon (Pwn) Diffuse This is a puzzle-type challenge. Each individual step is easy; the difficulty lies in finding every clue...


01 Oct 2024

web3, web, rev

TISC'24 Writeups #2

This is a continuation of my TISC writeups. This post will cover stage 6-9. Level 6: Noncevigator (Web3) Level 7: Baby Flagchecker (Web3/Rev) Level 8: Wallfacer (Rev) Level 9: Imphash (Pwn) Noncevigator We are given a Solidity smart contract Noncevigator.sol, with the challenge description: 1 2 3 It seems like...


01 Oct 2024

web, rev, forensics

TISC'24 Writeups #1

Over the past week or so, I have been playing TISC, CSIT’s annual CTF. I managed to solve all 12 challenges in 11 days, coming in 1st. TISC is an individual CTF hosted by CSIT that is open to all Singaporeans. The challenges roughly get progressively more difficult. You must...


16 Apr 2024

pwn, blockchain, vm

baby-bear-blockchain Writeup

This was a pwn challenge from the recent Amateurs CTF that I first-blooded. The challenge utilised an internal VM from a Solana validator client, Firedancer, and involved finding vulnerabilities in the VM implementation. Interestingly, Firedancer is a clone of the Rust Solana rbpf library but re-written in C! To temper...


02 Oct 2023

pwn, web, cloud, rev, forensics, crypto

TISC'23 Writeups

Palindrome, everyone’s favourite cybercrime syndicate, is back for TISC 2023. I managed to solve all 10 challenges this year and clinch 2nd place. Here are my write-ups for all 10 levels. Level 1: Disk Archaeology Level 2: XIPHEREHPIX’s Reckless Mistake Level 3: KPA Level 4: Really Unfair Battleships Game Level...


03 Sep 2023

pwn

DUCTF'23 Writeups

Over the weekend, I played DownUnderCTF with my team, Social Enginner Experts, placing 6th overall.


12 Jun 2023

pwn

SEETF'23 Author Writeups

This weekend, Social Engineering Experts (SEE) held its inaugural SEETF. Here are my write-ups for the challenges I authored. I am aware of the (multiple) unintended solutions, but thought it would be good to document my intended solutions. Thanks to everyone who played!


21 May 2023

pwn, rev

GreyCTF pwn write-ups

Over the weekend, I played GreyCTF with Social Engineering Experts, placing 1st locally and 8th internationally. Having not touched CTFs for ages due to NS, I was a bit rusty, but luckily the challenges were nice twists on simple concepts, offering a pleasant mix of difficulty. I focused on the...


23 Oct 2022

pwn, rev

JadeCTF pwn & rev write-ups

I participated in JadeCTF over the weekend. Having put CTFs on hold for some time for school, these challenges were a nice refresher for me. For these write-ups, I won’t be diving too deep into the details. Instead, I’ll mainly be focusing on the high-level method used to solve the...


31 Aug 2022

pwn, web, cloud, rev, forensics, crypto

CSIT TISC 2022 Write-ups

TISC (The InfoSecurity Challenge) 2022, organised by CSIT, was a CTF held over 17 days. Eager to escape my exam prep, I spent the first few days trying the challenges :) I solved the first 6 challenges in the first week before deciding to resume my studying… The challenges are...


25 Jun 2022

pwn

CDDC Write-ups (ring 3 pwn)

I felt that these ring’s challenges were quite fun, requiring some creative thinking to solve. There was one last challenge in this category which my team didn’t manage to solve (blackbox FSB pwn). You can find the relevant binaries in this repo.


25 Jun 2022

pwn

CDDC Write-ups (ring 4 pwn)

These 3 challenges had a wide variation in difficulty, but were all worth 100 points each (static scoring). You can find the relevant binaries in this repo.


25 Jun 2022

pwn

CDDC Write-ups (ring 5 pwn)

In the recent Cyber Defenders Discovery Camp (CDDC) organised by DSTA, my team ā€œAvocado_Milkā€ came in 4th with an overall score of 6180 - maybe one day I’ll get that podium finish :). Here are the write-ups for the challenges I solved during the CTF. I’ll be releasing my rev...