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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No solved challenges yet.

Today's Challenge

Submissions (latest 3)

apender

SOLVED!

Aug 29, 8:02 AM

xnmhuveb

SOLVED!

Aug 29, 7:20 AM

kurokane-isumi

SOLVED!

Aug 29, 6:25 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.

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

69 solves

2501

Anyrunner

Misc

Medium

65 solves

tchen

Small Image Uploader 2

Web

Medium

62 solves

admin

Día Nacional de la Alpaca

Misc

Welcome🌱

235 solves

2501

Password, Please

Misc

Easy🌱

201 solves

3-4

ark

Long Long Flag Printer 2026

Misc

Medium

94 solves

pppp4649

Happy Birthday

Crypto

Easy🌱

130 solves

6-8

hiikunz

AESAESAESAESAESAES

Crypto

Hard

60 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

82 solves

13-15

tchen

True or False 2

Misc

Hard

53 solves

16-17

tchen

List Sharing

Web

Medium

76 solves

tchen

List Sharing

Web

Medium

76 solves

18-20

tan90909090

wrong instruction

Rev

Hard

59 solves

21-23

tchen

Greetings i18n 2

Web

Hard

51 solves

24-26

tchen

Xwitter

Web

Hard

37 solves

27-28

tan90909090

Let's analyze system calls

Rev

Medium

44 solves

29-31

tchen

Springing

Web

Medium

24 solves

tchen

Springing

Web

Medium

24 solves

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for Xwitter

tchen

author

Xwitter

2 hours ago

Writeup for Let's analyze system calls

baumroll1234

Let's analyze system calls

3 hours ago

Writeup for Flag is A+B

alpha0314sub

Flag is A+B

6 hours ago

Writeup for Let's analyze system calls

mizore-fuyu

Let's analyze system calls

8 hours ago

Writeup for Encoding Basics

power

Encoding Basics

2026/08/26 12:20

Writeup for Bars

power

Bars

2026/08/26 08:34

Writeup for Vending Machine

haruhana

Vending Machine

2026/08/26 01:41

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

Rows:

Springing

Topic: AuthorizationReleased: Aug 29, 2026

24 solves

Web

Medium4.0

tchen

USER	SOLVED AT
apender	2 minutes ago
xnmhuveb	44 minutes ago
kurokane-isumi	1 hour ago
mizore-fuyu	2 hours ago
goroshirow	3 hours ago
commend4161	4 hours ago
kojikazu2005	4 hours ago
a01sa01to	5 hours ago
logdav	6 hours ago
f1023n	6 hours ago
edwowmath	7 hours ago
kapumoka	7 hours ago
bhcnumas	10 hours ago
cocoa	14 hours ago
goat-antony2008	14 hours ago
toomer	15 hours ago
mti	15 hours ago
gin	15 hours ago
kurgm	16 hours ago
bsvac	16 hours ago
rsk0315	16 hours ago
panya	16 hours ago
syn9	16 hours ago
umineko	17 hours ago

Rows:

description solves