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Daily AlpacaHack

A CTF challenge series with fun puzzles to enjoy every day

What is Daily AlpacaHack?

We regularly publish simple, beginner-friendly or educational CTF challenges!

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Solve each challenge within its time window to appear on the leaderboard.

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Today's Challenge
k0080k0080
what is my pointer 2
Pwn
Hard
25 solves
Submissions (latest 3)
stepbystepbymyself

SOLVED!

Sep 28, 1:49 PM

nirvana

SOLVED!

Sep 28, 11:39 AM

Leaderboard

Try the first challenge

Is this your first CTF? Let's begin by tackling the first challenge released on Daily AlpacaHack.

View challenge
admin
AlpacaHack 2100
Misc
Welcome🌱
2,227 solves
Upcoming challenges reveal the , , and in advance.
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Sep 2026

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tchentchen
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1
admin
QUIZ ALPACASHOCK
Misc
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2
hiikunzhiikunz
base 16-32-64
Misc
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5
baumroll1234
6-8
minaminaominaminao
Bitflip RSA
Crypto
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minaminaominaminao
Bitflip RSA
Crypto
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\^o^/
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sin function vs. fsin instruction
Rev
Misc
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Misc
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16-18
edwowmathedwowmath
neighboRhood_diStAnce
Crypto
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42 solves
19-21
hiikunzhiikunz
nested eval
Misc
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hiikunzhiikunz
nested eval
Misc
Hard
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22-24
2501
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Rev
Medium
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27-30
k0080k0080
what is my pointer 2
Pwn
Hard
25 solves
 
k0080k0080
what is my pointer 2
Pwn
Hard
25 solves
1
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2
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Writeups

Writeup for Leaked Flag Checker

paulayground

ko
Leaked Flag Checker

6 hours ago

gattoartz

Writeup for base 16-32-64

ja

2026/09/26 23:00

Rows:

Leaked Flag Checker

Topic: C, Flag CheckerReleased: Dec 4, 2025

704 solves
Rev
Easy🌱2.0

by

minaminao

minaminao

flag checker everyone loves

Beginner Hint
  • This challenge is in the Rev (Reverse Engineering) category.
  • Flag checkers are a common theme in Rev problems.
  • A flag checker executable or script accepts player input and tells you whether it matches the flag.
  • The provided files are the C source challenge.c and its Ubuntu 24.04 binary build challenge.
  • In challenge.c, the flag-related string xor_flag has been edited out and hidden.
  • The goal is to use challenge.c as a reference and find an input (the flag) that makes the challenge binary print Correct.
  • Typically Rev problems don't include source code. You usually analyze only the binary. This one can also be solved without the source.
leaked-flag-checker.tar.gz

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