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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
2501
Lean as a Service
Misc
Medium
35 solves
Submissions (latest 3)
jam-yabusame

SOLVED!

Oct 31, 1:16 AM

ctf-udon

SOLVED!

Oct 30, 3:40 PM

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🌱
2,327 solves
Upcoming challenges reveal the , , and in advance.
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Oct 2026

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k0080k0080
what is my pointer 2
Pwn
Hard
50 solves
1
admin
Baby Alpaca
Misc
Welcome🌱
173 solves
2
tan90909090tan90909090
C# File-based app
Rev
Easy🌱
87 solves
3-4
2501
Shared Prime
Crypto
Medium
92 solves
5-8
tan90909090tan90909090
fsbase modification
Pwn
Hard
64 solves
9-12
2501
Almost Shared Prime
Crypto
Hard
46 solves
 
2501
Almost Shared Prime
Crypto
Hard
46 solves
13-14
tan90909090tan90909090
cowsay jail
Misc
Medium
63 solves
15-18
hiikunzhiikunz
decreasing
Misc
Hard
35 solves
19-22
tan90909090tan90909090
x32 ABI flag checker
Rev
Hard
34 solves
23-24
pppp4649pppp4649
Σecret
Crypto
Easy🌱
52 solves
25-28
k0080k0080
what is my pointer 4
Pwn
Hard
39 solves
 
k0080k0080
what is my pointer 4
Pwn
Hard
39 solves
29-31
2501
Lean as a Service
Misc
Medium
35 solves
1
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Writeups

claritys

Writeup for login-bonus (English)

claritys

en
login-bonus

53 minutes ago

claritys

Writeup for Integer Writer (with brief explanation)

tadanobutubutu

Writeup for what is my pointer 4

tadanobutubutu

Writeup for Σecret

ja

2026/10/24 16:37

Rows:

hit-and-miss

Topic: RegexReleased: Dec 9, 2025

464 solves
Misc
Easy🌱3.5

by

ark

ark

USER

SOLVED AT

9b9fc

11 hours ago

2026/10/28 12:34

2026/10/21 18:32

2026/10/20 05:52

2026/10/15 06:50

2026/10/12 17:48

2026/10/10 14:44

2026/10/07 14:18

2026/10/06 01:48

2026/10/03 21:57

2026/09/06 12:00

2026/08/31 13:00

2026/08/22 12:45

2026/08/21 04:45

2026/08/14 21:04

2026/08/12 04:31

2026/08/08 03:24

2026/08/07 10:00

2026/08/06 10:38

2026/08/05 18:44

2026/08/04 13:02

2026/08/04 12:45

2026/08/03 07:05

2026/07/30 12:18

2026/07/30 08:33

Rows:

descriptionsolveswriteups