AlpacaHack Logo
Sign InSign Up
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

0

/11

No solved challenges yet.

Sign In to view your player stats

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.
Prev

Oct 2026

Next
Solved
Unsolved
Upcoming
Mon
Tue
Wed
Thu
Fri
Sat
Sun
 
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
Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

claritys

Writeup for alloc-101

claritys

en
alloc-101

22 minutes ago

claritys

Writeup for login-bonus (English)

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:

fake-shuffle-proof

Topic: Broken CommitmentReleased: Apr 20, 2026

139 solves
Crypto
Easy🌱2.5

by

shiro

USER

SOLVED AT

9b9fc

2026/10/30 07:38

2026/10/30 00:50

2026/09/26 07:25

2026/09/23 15:03

2026/09/14 00:50

2026/09/03 08:30

2026/09/02 18:27

2026/08/31 04:07

2026/08/30 08:06

2026/08/23 03:08

2026/08/16 15:38

2026/08/12 10:18

2026/08/10 16:06

2026/08/01 05:37

2026/07/09 15:31

2026/07/02 08:28

2026/06/30 14:31

2026/06/25 05:12

2026/06/17 07:27

2026/06/02 11:34

2026/05/21 04:41

2026/05/14 02:12

2026/05/05 02:29

2026/05/04 15:34

2026/05/04 15:26

Rows:

descriptionsolveswriteups