Activity log

I built a Windows app, “PasteDrawer”

A clipboard history tool you pull out from the screen edge and paste from by drag and drop. The product site is now up.

Released the game “Security Pachi-Slot”

Released a Juggler-style browser slot parodying “security pachinko,” the meme for AI-driven vulnerability research.

Released the game “Cheat Shogi”

Released a shogi game where cheat cards bend the rules — play the CPU or a friend online with a room ID.

Published the msfvenom one-liner generator

Added a browser tool that generates msfvenom commands and listeners from a dropdown.

Published the Web CheatSheet

Added a pentest / CTF command and technique cheatsheet to the site.

Relaunched yunolay.com

Moved the blog to blog.yunolay.com and rebuilt this site as a home for my activity log and works.

Moved to Fore-Z as Executive Officer ↗

Transferred from Executive Officer at Fore-co.ltd to Executive Officer at Fore-Z.

Spoke at OffSecLab Meetup in Shibuya

Gave a talk “OSEE受験記 (OSEE exam write-up)” as Yunolay, introducing OSEE and my exam experience.

OffSec Exploitation Expert (OSEE)

Earned by passing the EXP-401 (Advanced Windows Exploitation) exam — advanced exploit development including the Windows kernel.

Started writing on note ↗

Published my first article — a self-introduction — on May 17, 2026, and have been posting on note since.

Attended “Practical iOS Reverse Engineering” at OffensiveCon 2026

Took Jiska Classen’s training on reverse engineering iOS apps, kernel and firmware.

Attended “Windows Internals for Security Engineers” at OffensiveCon 2025

Took Yarden Shafir’s training on Windows 11 kernel internals and security mechanisms.

HTB Certified Web Exploitation Expert (CWEE)

Hack The Box’s advanced web exploitation certification.

Executive Officer, Fore-co.ltd

Executive management and security strategy.

Ran a workshop at RWPL in SECCON 13

Ran my self-made challenge “RWPL Flowers” hands-on, walking through source-code leakage via LFI and RCE.

Joined the Synack Red Team (SRT) ↗

Vulnerability research and red teaming.

HTB Certified Penetration Testing Specialist (CPTS)

Hack The Box’s penetration testing certification.

Security Engineer, Poruto-inc ↗

Vulnerability assessment and penetration testing.

Started freelancing

Independent security consulting and research.

Completed TryHackMe Advent of Cyber 2023

HTB Certified Web Exploitation Specialist (CWES, formerly CBBH)

Hack The Box’s web exploitation certification, earned under its former name CBBH.

Left GMO Cybersecurity by Ierae

About two years and nine months of web/API assessments and mobile game anti-cheat analysis.

OffSec Certified Expert 3 (OSCE3)

Awarded for holding all three of OSWE, OSEP and OSED.

OffSec Exploit Developer (OSED)

Windows user-mode exploit development.

OffSec Experienced Penetration Tester (OSEP)

Advanced penetration testing including evasion and Active Directory.

OffSec Web Expert (OSWE)

White-box web application exploitation and exploit automation.

Joined GMO Cybersecurity by Ierae

Assessed PHP, REST API, GraphQL, gRPC and Cloud Firestore targets.

eLearnSecurity eWPTXv2

Web Application Penetration Tester eXtreme.

eLearnSecurity eCPPTv2

Certified Professional Penetration Tester.

OffSec Certified Professional (OSCP)

The 24-hour hands-on penetration testing exam.

Left LAC Co., Ltd.

Operated IPS, IDS, WAF and sandboxes in the SOC (FireEye, Palo Alto, Cisco, Juniper).

Joined LAC Co., Ltd. (SOC)

Started my career in a security operations center.