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!

Join Anytime

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

Not a Competition

Discussion with friends or AI is welcome (account sharing is prohibited).

Solution Sharing Rules

Sharing solutions is allowed only after the challenge period has ended.

Solve stats

No solved challenges yet.

Today's Challenge

Submissions (latest 3)

tadanobutubutu

SOLVED!

Oct 23, 11:14 AM

curetwinkle

SOLVED!

Oct 23, 9:55 AM

lluuiiggee

SOLVED!

Oct 23, 5:51 AM

Leaderboard

Period

Try the first challenge

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

Upcoming challenges reveal the , , and in advance.

Oct 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

k0080

what is my pointer 2

Pwn

Hard

47 solves

admin

Baby Alpaca

Misc

Welcome🌱

154 solves

tan90909090

C# File-based app

Rev

Easy🌱

76 solves

3-4

2501

Shared Prime

Crypto

Medium

86 solves

5-8

tan90909090

fsbase modification

Pwn

Hard

59 solves

9-12

2501

Almost Shared Prime

Crypto

Hard

44 solves

2501

Almost Shared Prime

Crypto

Hard

44 solves

13-14

tan90909090

cowsay jail

Misc

Medium

59 solves

15-18

hiikunz

decreasing

Misc

Hard

34 solves

19-22

tan90909090

x32 ABI flag checker

Rev

Hard

29 solves

23-24

pppp4649

Σecret

Crypto

Easy🌱

25 solves

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for x32 ABI flag checker

tadanobutubutu

x32 ABI flag checker

1 hour ago

Writeup for Mirage

haruhana

Mirage

2026/10/22 02:56

Writeup for decreasing

umineko

decreasing

2026/10/19 10:40

Writeup for decreasing

blackade

decreasing

2026/10/18 15:20

Writeup for login-bonus-3

lumma

2026/10/18 07:01

Writeup for Slipboard

umachaba

Slipboard

2026/10/16 09:41

Writeup for fsbase modification

ojun

fsbase modification

2026/10/15 13:59

Writeup for Rate My Alpaca

umachaba

Rate My Alpaca

2026/10/15 09:00

Writeup for cowsay jail

tadanobutubutu

cowsay jail

2026/10/15 08:42

Writeup for Almost Shared Prime

tadanobutubutu

Almost Shared Prime

2026/10/15 08:35

Rows:

Emojify

Topic: Server-SideReleased: Dec 3, 2025

773 solves

Web

Medium4.5

ark

Tags

Writeups

Writeup for Emojify

paulayground

2026/05/20 15:17

Writeup for Emojify

chjwoo

2025/12/03 15:06

Writeup for Emojify

minaminao

2025/12/04 01:29

Writeup for Emojify

dora

2025/12/06 03:38

Writeup for Emojify

sigchill

2025/12/06 16:51

Writeup for Emojify

neglect-yp

2025/12/10 12:49

Daily AlpacaHack 1週間目Writeup 12/01~12/07

trimscash

2025/12/14 13:02

Writeup for Daily AlpacaHack 12/1-12/5

tikisan0531

2025/12/15 12:12

Daily AlpacaHack Week 1 (2025-12-01 〜 2025-12-07)

n0name

2025/12/21 05:39

Writeup for Daily Challenge (2025/12/1~2025/12/7)

labpump

2025/12/29 09:04

Writeup for Emojify

gattoartz

2026/01/25 04:11

description solves writeups