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)

chara0x

SOLVED!

Aug 26, 4:22 AM

logdav

SOLVED!

Aug 26, 4:08 AM

itsuki-t

SOLVED!

Aug 25, 4:04 PM

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.

Aug 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

tchen

RFC100008

Web

Easy🌱

142 solves

2501

One More Approval

Crypto

Medium

61 solves

2501

zen.zip

Misc

Medium

68 solves

2501

Anyrunner

Misc

Medium

65 solves

tchen

Small Image Uploader 2

Web

Medium

61 solves

admin

Día Nacional de la Alpaca

Misc

Welcome🌱

223 solves

2501

Password, Please

Misc

Easy🌱

191 solves

3-4

ark

Long Long Flag Printer 2026

Misc

Medium

93 solves

pppp4649

Happy Birthday

Crypto

Easy🌱

124 solves

6-8

hiikunz

AESAESAESAESAESAES

Crypto

Hard

59 solves

9-10

tchen

Not so Pyf**k

Misc

Medium

84 solves

tchen

Not so Pyf**k

Misc

Medium

84 solves

11-12

baumroll1234

Fermat's Last Theorem

Misc

Medium

80 solves

13-15

tchen

True or False 2

Misc

Hard

53 solves

16-17

tchen

List Sharing

Web

Medium

73 solves

tchen

List Sharing

Web

Medium

73 solves

18-20

tan90909090

wrong instruction

Rev

Hard

58 solves

21-23

tchen

Greetings i18n 2

Web

Hard

50 solves

24-26

tchen

Xwitter

Web

Hard

30 solves

27-28

tan90909090

Planned topicSystem Call

Rev

Medium

29-31

tchen

Planned topicAuthorization

Web

Medium

tchen

Planned topicAuthorization

Web

Medium

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for Bars

power

Bars

34 minutes ago

Writeup for Vending Machine

haruhana

Vending Machine

7 hours ago

Writeup for wrong instruction

umineko

wrong instruction

2026/08/22 05:08

Writeup for You are my friend

haruhana

You are my friend

2026/08/21 02:40

Writeup for wrong instruction

baumroll1234

wrong instruction

2026/08/20 21:20

Writeup for Plz Login

haruhana

Plz Login

2026/08/20 03:21

Writeup for Leaked Flag Checker

power

Leaked Flag Checker

2026/08/18 11:53

Writeup for Password, Please

power

Password, Please

2026/08/18 03:26

Writeup for List Sharing

baumroll1234

List Sharing

2026/08/17 20:44

Writeup for Ruby Flag Checker

haruhana

Ruby Flag Checker

2026/08/16 03:34

Rows:

Vending Machine

Topic: PythonReleased: May 8, 2026

213 solves

Misc

Easy🌱2.5

baumroll1234

Tags

Writeups

Writeup for Vending Machine

baumroll1234

author

2026/05/09 13:21

Writeup for Vending Machine

nozokare

2026/05/09 08:12

Writeup for Daily AlpacaHack 5/3-5/9

kakur41

2026/05/09 15:23

AlpacaHackで始めるCTF入門8：初めてのDaily AlpacaHackに挑戦

yusukekato

2026/05/10 07:04

Writeup for Daily AlpacaHack 5/4-5/10

labpump

2026/05/16 13:27

Writeup for Vending Machine

goroshirow

2026/05/08 15:19

Writeup for Vending Machine

th0rn

2026/05/09 02:20

Daily AlpacaHackに挑戦するつくよみちゃん 05/08 misc/Vending Machine/baumroll1234

tsukuyomi-chan

2026/05/09 09:16

Writeup for Vending Machine

tadanobutubutu

2026/05/09 10:29

Writeup for Vending Machine

haruhana

7 hours ago

description solves writeups