Harold Kim
Backend Developer • Security Researcher
github stypremail me@harold.kim  ‹pubkey›   ctftime stypr


Full-time Security Researcher, SEWorks Inc. Sept 2018 -
0 month
» Mainly focusing on web security researches and automation analysis.
» Developing and Maintaining flagship products.
Signaller, ROK Army Nov 2016 - Aug 2018
1y 8 months
» Discharged as Sergeant. Received many awards while wokring in the army.
» Maintained internal systems, managed and monitored security firewalls.
» Building CCTV cameras on blind spots and making secure LAN cables.
Full-time Security Researcher, SEWorks Inc. June 2014 - Nov 2016
2y 4 months
» Focusing mainly on core server management and backend service development.
» Developed core products, including product maintanence. (Uses python, GoLang+Redis, PHP, Java, etc.)
» Frequently performs vulnerability checks and penetration tests on core products.
» Security/development researches for future developments.


Undergraduate Student, University of Toronto Sept. 2014 - June 2015
9 months
» Currently studying as an undergraduate, and is going to acquire a Bachelor’s degree.
» Currently on a long leave for jobs.
International Baccalaureate Diploma Sept. 2012 - June 2014
1y 9 months
» Acquired International Baccalaureate Diploma for Secondary School.
» Studied in an Indian International school.
(Physics HL, Computer Science HL, Mathematics HL, English B HL, Korean A SL, Economics SL)


2017 Finalist, CodeGate CTF 2017 Seoul, South Korea
2016 1st place @ CTFTime! \o/
2016 2nd place, EKOPARTY CTF 2016 Latin America
2016 2nd place, Silk Road CTF 2016 Karamay, China
2016 1st place, ASIS CTF Finals Tehran, Iran
2016 1st place, C4CTF 2016 Riyadh, Saudi Arabia
2016 1st place, TU CTF 2016 Tulsa, OK
2016 1st place, Sharif University CTF Tehran, Iran
2016 2nd place, Internetwache CTF Berlin, Germany
2016 Finalist, PHDays 2016 Moscow, Russia
2015 1st place, Hack Zone Tunisia 2015 Manouba, Tunisia
2015 1st place, Break In 2015 Hyderabad, India
2015 Finalist, CSAW CTF 15 Hacking Competition NA Finals Brooklyn, NY
2014 Finalist, CSAW CTF 14 Hacking Competition NA Finals Brooklyn, NY
2014 Finalist, DEFCON 22nd CTF Hacking Competition World Finals Las Vegas, NV
2014 2nd place. Olympic Sochi CTF 2015 (Acquired DEFCON Qualifier)
2015 1st place, 14th HUST Hacking Festival Seoul, South Korea
2015 1st place, 2015 Inc0gnito Hacking Competition Seoul, South Korea
2018 1st place, Korean Army Hacking Defense Contest Daejeon, South Korea
» I’m not participating in any CTF team at the moment.
» I’ve done a lot of competitions so far. Writeups on some of these are archived in github.


CTF Organizer and Challenge Author 2014 - PRESENT
2014-2016 Organizer, KAIST and POSTECH Science War (Hacking Part)
2018 Author, moehost and gameshop, ASISCTF 2018 Quals
  More to come...
Web Fuzzer Development and its Utilization June 2014
Talked on WOWHACKER 2nd Seminar. Seoul, Korea

» a.k.a. Introduction to web fuzzer development.
» Demonstrated the process of web fuzzer development and its utilization, including the practical usage of fuzzers and its utilizations.
» Presentations available at //goo.gl/VabWPK
Stereotyped Challenges Oct. 2014 - PRESENT
3y 10 months

» Operating and developing a website consisting of extremely technical offensive security challenges.
» Sourcecode is currently available at //github.com/stypr/chall.stypr.com


Language ASM (Beginner), C (Mediocre), Go (Mediocre), Java (Fluent), PHP (Native), Python (Native), SQL (Native), VB (Native).
Korean (Native), English (Native), Mandarin (Poor), Japanese (Poor)
Softwares WireShark, Chrome/Firefox devtools, WireShark, Hex-rays, My Own Fuzzer, x64dbg, NetCat, Fiddler
HeidiSQL, HxD, Git, VMWare/qemu, ESXi, etc.