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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
tan90909090tan90909090
x32 ABI flag checker
Rev
Hard
6 solves
Submissions (latest 3)
gin

SOLVED!

Oct 18, 5:30 PM

Leaderboard

Try the first challenge

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

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admin
AlpacaHack 2100
Misc
Welcome🌱
2,288 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
47 solves
1
admin
Baby Alpaca
Misc
Welcome🌱
141 solves
2
tan90909090tan90909090
C# File-based app
Rev
Easy🌱
72 solves
3-4
2501
Shared Prime
Crypto
Medium
79 solves
5-8
tan90909090tan90909090
fsbase modification
Pwn
Hard
58 solves
9-12
2501
Almost Shared Prime
Crypto
Hard
42 solves
 
2501
Almost Shared Prime
Crypto
Hard
42 solves
13-14
tan90909090tan90909090
cowsay jail
Misc
Medium
57 solves
15-18
hiikunzhiikunz
decreasing
Misc
Hard
30 solves
19-22
tan90909090tan90909090
x32 ABI flag checker
Rev
Hard
6 solves
23
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Coming soon
25
Coming soon
26
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Writeups

Writeup for decreasing

blackade

ja
decreasing

2 hours ago

ojun

Writeup for fsbase modification

ja

2026/10/15 13:59

tadanobutubutu

Writeup for cowsay jail

ja

2026/10/15 08:42

tadanobutubutu

Writeup for Almost Shared Prime

nirvana

Writeup for cowsay jail

ja

2026/10/14 21:19

Rows:

super-tomato

Topic: Number TheoryReleased: Jan 2, 2026

469 solves
Crypto
Easy🌱3.0

by

kanon

kanon

USER

SOLVED AT

y0dam4n

2026/10/14 07:09

2026/10/12 14:40

2026/10/12 05:43

2026/10/11 19:40

2026/10/10 16:48

2026/10/10 12:05

2026/10/07 15:23

2026/10/07 00:34

2026/10/02 08:58

2026/09/16 05:05

2026/09/07 12:04

2026/09/04 12:58

2026/09/03 09:05

2026/09/03 03:04

2026/08/31 12:52

2026/08/31 00:30

2026/08/29 07:18

2026/08/28 15:31

2026/08/22 15:27

2026/08/19 14:03

2026/08/18 08:17

2026/08/15 17:05

2026/08/13 14:52

2026/08/11 13:19

2026/08/10 23:46

Rows:

descriptionsolveswriteups