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GreyCTF Summit 2025
2025-07-05

My Journey to GreyCTF Summit 2025#

The journey to the summit was an adventure in itself! Here’s how I got there:

  1. P211 Bus to Larkin Sentral
  2. P201 Bus to JB Sentral
  3. Train to Woodlands CIQ, Singapore
  4. Bus to Woodlands MRT
  5. SMRT to Kent Ridge MRT
  6. NUS Bus to the School of Computing

Trip


A Rough Start#

Missed KTMB

Missed Train

Unfortunately, I missed my train to Singapore. Lesson learned: always arrive at least 30 minutes early.

To make up for it, I decided to take the bus to Woodlands. It was a longer route, but I eventually made it. RIP my wallet…


Sessions#

TimeSession
1020h - 1230hWorkshop: Active Directory
1230h - 1400hLunch & Networking
1400h - 1430hTalk 1: Linux Internal eBPF
1430h - 1500hTalk 2: AI in Cybersecurity
1500h - 1530hTalk 3: Intro to Fuzzing
1530h - 1630hTalk 4: Behind The Scenes of GreyCTF

Workshop: Active Directory#

Presented by RangeVillage, this hands-on workshop covered Active Directory security fundamentals, including enumeration techniques, privilege escalation methods, and attack path discovery.

We used tools such as:

  1. NXC - NetExec - The Network Execution Tool (Enumeration and Execution)
  2. Evil WinRM
  3. Impacket
  4. bloodyAD
  5. mimikatz

During the breaks, I visited sponsor booths and caught several demos, which unfortunately caused me to miss parts of the tutorial.

Resources:


Talk 1: Linux Internal eBPF#

This one covered about linux internal stuff, cool and didn’t know much about. eBPF


Talk 2: AI in Cybersecurity#

This session covered how large language models gather intelligence from the dark web and index it in a vector database. By querying this database, participants could retrieve up-to-date, filtered information on advanced persistent threats (APTs).

AI


Talk 3: Intro to Fuzzing#

I learned that fuzzing is a software testing technique that feeds unexpected or random inputs to an application to uncover bugs and ensure it handles edge cases gracefully without crashing.

They introduced powerful fuzzing tools such as LibFuzzer, which automate test case generation and help uncover edge-case bugs efficiently.

Fuzzing


Talk 4: Behind The Scenes of GreyCTF#

This session was led by the GreyCTF challenge creators, who walked us through their design process—how they develop challenges, adjust difficulty, and refine problem statements.

They also provided an in-depth overview of the custom badge’s internal architecture and its design considerations: Hardware_Slides


Hardware Hacking#

For me, the highlight of the summit was the hardware hacking booth. I learned so much about working with hardware, and it was incredibly rewarding.

One of the coolest parts was the custom badge they provided. It was built on a Field-Programmable Gate Array (FPGA) and could be programmed using CircuitPython. This hands-on experience was both fun and educational.

So, first they introduced some quizzes that must be solved before going to the next stage…

After that, the real hacking begins, this is the same challenge used for in the GreyCTF Finals.

Adafruit FPGA Badge

The custom FPGA badge provided to participants. Custom FPGA Badge


Photo Gallery#

Booth Bingo Booth

Food by Grain Food

Photos I took in NUS NUS

GreyCTF Summit 2025
https://fuwari.vercel.app/posts/greyctfsummit-2025/
Author
Bakayang
Published at
2025-07-05
License
CC BY-NC-SA 4.0