Writeups

A collection of some writeups written by TJCSC

Haix-la-Chapelle 2025 - PDFBill (Misc)

11/30/2025 — 9 min readAutomating UUID hoarding to break the Cloud Bill Insurance credit limit and buy the premium voucher.

Andrew Liu

PatriotCTF 2025 - Waldo's Night Out (OSINT)

11/30/2025 — 3 min readTriangulating Sterling, Reston, and Tysons for the multi-part Waldo's Night Out challenge

Ansh Agrawal

LakeCTF 2025 - Attack of the Clones (Crypto)

11/28/2025 — 7 min readCrypto walkthrough for Attack of the Clones

Ansh Agrawal

LakeCTF 2025 - Ez Part (Crypto)

11/28/2025 — 8 min readCrypto walkthrough for Ez Part

Ansh Agrawal

LakeCTF 2025 - Gamblecore (Web)

11/28/2025 — 5 min readWeb walkthrough for Gamblecore

Ansh Agrawal

LakeCTF 2025 - Guess Flag (Crypto)

11/28/2025 — 4 min readCrypto walkthrough for Guess Flag

Ansh Agrawal

LakeCTF 2025 - Quantum vernam (Crypto)

11/28/2025 — 5 min readCrypto walkthrough for Quantum vernam

Ansh Agrawal

LakeCTF 2025 - Revenge of the Sith (Crypto)

11/28/2025 — 6 min readCrypto walkthrough for Revenge of the Sith

Ansh Agrawal

LakeCTF 2025 - The Phantom Menace (Crypto)

11/28/2025 — 4 min readCrypto walkthrough for The Phantom Menace

Andrew Liu

PatriotCTF 2025 - Where's Legally Distinct Waldo Four (OSINT)

11/27/2025 — 1 min readOSINT walkthrough for the fourth Waldo challenge

Andrew Liu

PatriotCTF 2025 - Where's Legally Distinct Waldo One (OSINT)

11/27/2025 — 2 min readOSINT walkthrough for the first Waldo challenge

Andrew Liu

PatriotCTF 2025 - Where's Legally Distinct Waldo Three (OSINT)

11/27/2025 — 1 min readOSINT walkthrough for the third Waldo challenge

Andrew Liu

PatriotCTF 2025 - Where's Legally Distinct Waldo Two (OSINT)

11/27/2025 — 1 min readOSINT walkthrough for the second Waldo challenge

Brian Ho

picoGym - SideChannel

3/1/2024 — 5 min readTiming-based side channel attack on an pin-checker program

Brian Ho

picoGym - Specialer

2/20/2024 — 3 min readReading files in a sandboxed environment

Darin Mao

ASIS CTF Finals 2021 - cuuurl

1/7/2022 — 5 min readArbitrary curl to RCE

Darin Mao

TetCTF 2022 - ezflag 2

1/7/2022 — 9 min readSimple ROP through a socket

Darin Mao

TetCTF 2022 - magicbox

1/7/2022 — 17 min readReversing a NOR machine

Darin Mao

redpwnCTF 2021 - devnull-as-a-service (pwn)

7/12/2021 — 14 min readret2dlresolve on 64-bit binaries with huge pages

Darin Mao

redpwnCTF 2021 - gelcode-2 (pwn)

7/12/2021 — 6 min readShellcode golfing

Darin Mao

picoMini by redpwn 2021 - Darin's Challenges

6/21/2021 — 18 min readAuthor writeups for picoMini by redpwn

Diana Lin

picoMini by redpwn 2021 - notepad (web)

5/12/2021 — 5 min readWriteup for notepad (web)

Diana Lin

picoMini by redpwn 2021 - not-crypto (rev)

5/12/2021 — 2 min readWriteup for not-crypto (rev)

Anna Hsu

picoMini by redpwn 2021 - advanced-potion-making (forensics)

5/11/2021 — 3 min readFixing a corrupt PNG file

Anna Hsu

picoMini by redpwn 2021 - login (web)

5/11/2021 — 2 min readClient side login seems like a bad idea

Darin Mao

ångstromCTF 2021 - Jar/Snake/Ekans

4/15/2021 — 16 min readExploiting heavily restricted pickle deserialization

Darin Mao

ångstromCTF 2021 - wallstreet (pwn)

4/15/2021 — 5 min readAn unusual trick for format string exploitation

Darin Mao and Daniel Wang

picoCTF 2021 - BitHug (web)

4/5/2021 — 5 min readExploiting SSRF in a complex web application

Darin Mao

picoCTF 2021 - Stonk Market (pwn)

3/31/2021 — 7 min readTricky format string exploitation

Darin Mao

picoCTF 2021 - Bizz Fuzz (pwn)

3/30/2021 — 7 min readAutomated analysis of a large binary

Darin Mao

justCTF 2020 - Pinata (pwn)

1/30/2021 — 18 min readBlind exploitation of nginx from justCTF 2020

Darin Mao, Saigautam Bonam, and Autin Mitra

TJCSC Winter Contest 2020

12/16/2020 — 23 min readSolutions to selected problems from the 2020 Winter Contest

Darin Mao and Stephen Huan

NACTF 2020

11/4/2020 — 14 min readRequired writeups for winning teams.

Darin Mao

CSAW CTF 2020 Qualifier - blox (rev/pwn)

11/3/2020 — 13 min readThis was a two-part series from the 2020 CSAW CTF Qualifier involving a small Tetris-like game.

Darin Mao

DamCTF 2020 - guess (pwn)

10/12/2020 — 3 min readThis is my writeup for the challenge "guess" in the pwn category from OSUSEC's DamCTF 2020.

Darin Mao

CSAW RED 2020 Qualifier (crypto)

9/29/2020 — 3 min readSolutions for crypto challenges from the CSAW RED 2020 Qualification Round.

Darin Mao

CSAW RED 2020 Qualifier (rev)

9/29/2020 — 17 min readSolutions for rev challenges from the CSAW RED 2020 Qualification Round.

Darin Mao

CSAW RED 2020 Qualifier (misc)

9/29/2020 — 13 min readSolutions for misc challenges from the CSAW RED 2020 Qualification Round.

Darin Mao

CSAW RED 2020 Qualifier (web)

9/29/2020 — 3 min readSolutions for web challenges from the CSAW RED 2020 Qualification Round.

Darin Mao

CSAW RED 2020 Qualifier (pwn)

9/29/2020 — 15 min readSolutions for pwn challenges from the CSAW RED 2020 Qualification Round.