balsn / balsn-ctf-2020

Archive of Balsn CTF 2020

Balsn CTF 2020

The top N domestic teams will be invited to another on-site competition on December 12th and 13th in Taipei, Taiwan.

• Date: 11/14 10:00 a.m. (UTC+8) ~ 11/16 10:00 a.m. (UTC+8)
• Format: Online Jeopardy
• CTFtime link
• Prize (the prize will be transferred in BTC or ETH.)
  • 1st place: $30,000 TWD
  • 2nd place: $23,000 TWD
  • 3rd place: $15,000 TWD
  • Balsn CTF 2020 Taiwan Stars (top 3 domestic teams, sponsored by HackerSir):
    • 1st place: $15,000 TWD
    • 2nd place: $10,000 TWD
    • 3rd place: $5,000 TWD

Results:

• 1st: Super ⚔️ Blue
• 2nd: The Flat Network Society
• 3rd: 10sec
• Balsn CTF 2020 Taiwan Stars (top 3 domestic teams):
  • 1st: 10sec
  • 2nd: NCtfU
  • 3rd: BambooFox

Challenges

• Balsn CTF 2020 - Challenges
  • Misc
    • Show your Patience and Intelligence I
    • Show your Patience and Intelligence II
    • IdleGame
    • Election
    • Transformer: The Guardian Knight
    • The Last Bitcoin
  • Crypto
    • aeshash
    • IEAIE
    • Happy Farm
  • Reverse
    • babyrev
    • The Danger of Google's Omnipotence
  • Web
    • Windows XP Media Player
    • The Woven Web
    • tpc
    • L5D
  • Pwn
    • Machbook Air
    • Machbook Pro
    • Diary
    • STACK
    • House of Cats

Misc

Show your Patience and Intelligence I

• Solved: 8
• Author: nawmrofed
• Link: https://hackmd.io/@KSmbxBXYS--LGCt0iZmypw/r19D6WoiD

Show your Patience and Intelligence II

• Solved: 24
• Author: nawmrofed
• Link: https://hackmd.io/@KSmbxBXYS--LGCt0iZmypw/r19D6WoiD

IdleGame

• Solved: 4
• Author: shw
• Link: https://github.com/x9453/my-ctf-challenges#balsn-ctf-2020

Election

• Solved: 5
• Author: shw
• Link: https://github.com/x9453/my-ctf-challenges#balsn-ctf-2020

Transformer: The Guardian Knight

• Solved: 10
• Author: sasdf
• Link:

The Last Bitcoin

• Solved: 50
• Author: kevin47
• Writeup: echo -en '\xff\n' | nc [ip] [port] The condition in run.sh will be passed if the process exit(1), which normally means that the verify_hash() returned True But it turns out that the process not terminating normally will also exit(1) Inputting \xff will crash python's input() because it can't be decoded to str as utf-8 If you execute run.sh locally, you can also simply press ctrl+c to get flag
• You can use nc the-last-bitcoin.balsnctf.com 7123 -N and Press ctrl+D

Crypto

aeshash

• Solved: 0
• Author: sasdf
• Link:

IEAIE

• Solved: 0
• Author: kevin47
• Link: HW

Happy Farm

• Solved: 10
• Author: fweasd
• Link:

Reverse

babyrev

• Solved: 33
• Author: sces60107
• Link:

The Danger of Google's Omnipotence

• Solved: 2
• Author: Frank Lin
• Link: https://www.notion.so/Balsn-CTF-2020-Writeup-The-Danger-of-Google-s-Omnipotence-2183588ae68548c3bf7648c24f756a3c

Web

Windows XP Media Player

• Solved: 5
• Author: bookgin
• Link: https://github.com/BookGin/my-ctf-challenges#balsn-ctf-2020

The Woven Web

• Solved: 6
• Author: bookgin
• Link: https://github.com/BookGin/my-ctf-challenges#balsn-ctf-2020

tpc

• Solved: 33
• Author: ysc
• Link: https://gist.github.com/YSc21/e5471285145cc5d34fe53c7d67a3d8f3

L5D

• Solved: 17
• Author: kaibro
• Link: https://github.com/w181496/My-CTF-Challenges/tree/master/Balsn-CTF-2020#l5d

Pwn

Machbook Air

• Solved: 4
• Author: how2hack
• Link: https://github.com/how2hack/my-ctf-challenges/tree/master/2020/balsnctf-2020/machbookair

Machbook Pro

• Solved: 1
• Author: how2hack
• Link: https://github.com/how2hack/my-ctf-challenges/tree/master/2020/balsnctf-2020/machbookpro

Diary

• Solved: 18
• Author: jwang
• Link: https://github.com/jwang-a/CTF/tree/master/MyChallenges/Pwn/Diary

STACK

• Solved: 0
• Author: jwang
• Link: HW
• Hint: https://github.com/jwang-a/CTF/tree/master/MyChallenges/Pwn/STACK

House of Cats

• Solved: 0
• Author: jwang
• Link: HW
• Hint: https://github.com/jwang-a/CTF/tree/master/MyChallenges/Pwn/House_of_Cats