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.

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Today's Challenge

Submissions (latest 3)

mak0tan

SOLVED!

Oct 24, 6:15 PM

goat-antony2008

SOLVED!

Oct 24, 5:59 PM

rsk0315

SOLVED!

Oct 24, 4:49 PM

Leaderboard

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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🌱

155 solves

tan90909090

C# File-based app

Rev

Easy🌱

77 solves

3-4

2501

Shared Prime

Crypto

Medium

87 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

60 solves

15-18

hiikunz

decreasing

Misc

Hard

34 solves

19-22

tan90909090

x32 ABI flag checker

Rev

Hard

31 solves

23-24

pppp4649

Σecret

Crypto

Easy🌱

40 solves

25-28

k0080

what is my pointer 4

Pwn

Hard

8 solves

k0080

what is my pointer 4

Pwn

Hard

8 solves

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for Σecret

tadanobutubutu

Σecret

6 hours ago

Writeup for Σecret

baumroll1234

Σecret

7 hours ago

Writeup for x32 ABI flag checker

tadanobutubutu

x32 ABI flag checker

2026/10/23 11:18

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

Rows:

Greetings i18n 2

Topic: PythonReleased: Aug 21, 2026

59 solves

Web

Hard7.5

tchen