Hello, I am
Atsuki Hakozaki
aka Yunolay
Security Engineer
Penetration Tester
Vulnerability Researcher
Exploit Developer
Red Team
01. About Me
I am a Security Engineer and Vulnerability Researcher based in Japan. My passion lies in Offensive Security, Bug Bounty Hunting, and Penetration Testing.
- Region: Japan
- Languages: Japanese, English (Studying)
- Interests: Anime, Manga, CTF
- Specialty: Web, API, Binary Exploitation
02. Skills & Arsenal
Programming & Scripting
Attacks
OS & Tools
03. Experience
April 2025 - Present
Executive Officer
Fore-co.ltd
- Executive management and security strategy
- Hybrid Work
Jan 2025 - Present
Synack SRT
Synack Red Team
- Vulnerability Research & Red Teaming
June 2024 - Present
Security Engineer
Poruto-inc
- Vulnerability Diagnosis & Penetration Testing
- Hybrid Work (Tokyo)
April 2024 - Present
Freelance
Freelance / Self-Employed
- Security Consulting & Research
- Tokyo, Japan
April 2021 - Dec 2023
Vulnerability Researcher
GMO Cybersecurity by Ierae, Inc.
- Web & API Vulnerability Diagnosis
- Smartphone Game Anti-Cheat Analysis
- Tech Stack: PHP, REST API, GraphQL, gRPC, Cloud Firestore
- Tokyo, Japan
April 2017 - May 2019
SOC Member & Security Engineer
LAC Co., Ltd.
- Operation of IPS, IDS, WAF, Sandbox
- Handled FireEye, PaloAlto, Cisco, Juniper devices
- Tokyo, Japan
04. Certifications
OffSec
- OSCP
- OSWE
- OSEP
- OSED
- OSCE3
HackTheBox
- HTB CWES
- HTB CPTS
- HTB CWEE
INE Security
- eCPPTv2
- eWPTXv2
National Exams
- IPA FE
- IPA AP
- IPA SC
05. Platforms & CTF
HackTheBox
Omniscient
190+ Systems Owned
Top 8 Global Rank (Peak)
picoCTF
10k+ Pts
General Skills: 100%
Awards
- MBSD Cybersecurity Challenge - 2nd Place
- HTB Open Beta Season III, IV, V, VI - Holo Rank
Teams
7h3B14ckKn1gh75 (Knights)