Vincent Yiu
Managing Director at SYON Security
Hong Kong Island, Hong Kong, China
Summary
🤩
Rockstar🎓
Top SchoolVincent Yiu is a Managing Director and seasoned red team leader with 11 years of experience helping organisations protect themselves by thinking like adversaries. Based in Hong Kong, he leads SYON Security’s advanced offensive services, combining hands-on exploit and tool development with strategic advisory and high-value red team engagements. His background spans elite consultancies and teams (Deloitte, MDSec, FusionX, Mitnick’s Ghost Team), where he specialised in Active Directory, Windows attack paths, and realistic threat simulation. An active researcher and tool author, his open-source projects include DomLink and LinkedInt—practical reconnaissance utilities that reflect his focus on domain discovery and automated profiling. He serves on the Defcon Adversary Village CFP Review Board and teaches red team techniques, bringing both public-facing thought leadership and battlefield-tested tradecraft to clients. Notably, Vincent mixes technical depth (weaponised PoCs and payload tools) with commercial leadership, often stepping into cross-functional roles such as interim financial controller to keep operations tightly aligned with delivery.
11 years of coding experience
6 years of employment as a software developer
Cybersecurity: Managing Risk in the Information Age, Cybersecurity: Managing Risk in the Information Age at Harvard UniversityMaster of Engineering (M.Eng.) with Honours Computer Science, Master of Engineering (M.Eng.) with Honours Computer Science at University of Warwick
English, Chinese, Chinese
Stackoverflow
1reputation
0reached
0answers
0questions
Github Skills (15)
apim10
command-line-interface10
configuration-management10
api10
python10
webscraping10
http-request10
command-line10
cli10
apidoc9
security9
user-authentication9
beautifulsoup9
authentication9
json8
Programming languages (19)
Github contributions (5)
vysecurity/DomLink
Apr 2018 - Apr 2021
A tool to link a domain with registered organisation names and emails, to other domains.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:31 commits, 15 PRs, 32 pushes in 3 years
Contributions summary:Vincent primarily worked on refactoring and improving the `domlink` tool, which appears to be for domain discovery. Their contributions include fixing an exception handling issue, incrementing the version number, and a large refactor described as "b4ldr refactor," implying major code restructuring. Additionally, the user added a banner and some formatting changes to improve usability.
pythondomain-nameemailemailswhois
vysecurity/LinkedInt
Mar 2018 - Jun 2021
LinkedIn Recon Tool
Role in this project:Back-end Developer & Security Engineer
Back-end Developer & Security EngineerContributions:2 releases, 40 commits, 12 PRs in 3 years 3 months
Contributions summary:Vincent significantly modified the LinkedInt.py script, a LinkedIn reconnaissance tool, enhancing its functionality and addressing security-related concerns. Their work included fixing authentication issues, integrating an API for email prediction, and updating the code to fetch profile pictures correctly. The user also refactored the code and fixed various typos, improving the overall maintainability and usability of the tool. Furthermore, the user appears to have removed a CSV and re-added a banner, indicating work around the program's data output and presentation.
recon-toolreconnaissancesecuritybugbountypenetration-testing
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