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)

yoshy

SOLVED!

Aug 31, 5:20 AM

hiikunz

SOLVED!

Aug 31, 5:13 AM

ahnmo

SOLVED!

Aug 31, 12:27 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🌱

145 solves

2501

One More Approval

Crypto

Medium

61 solves

2501

zen.zip

Misc

Medium

69 solves

2501

Anyrunner

Misc

Medium

67 solves

tchen

Small Image Uploader 2

Web

Medium

63 solves

admin

Día Nacional de la Alpaca

Misc

Welcome🌱

240 solves

2501

Password, Please

Misc

Easy🌱

206 solves

3-4

ark

Long Long Flag Printer 2026

Misc

Medium

95 solves

pppp4649

Happy Birthday

Crypto

Easy🌱

137 solves

6-8

hiikunz

AESAESAESAESAESAES

Crypto

Hard

60 solves

9-10

tchen

Not so Pyf**k

Misc

Medium

85 solves

tchen

Not so Pyf**k

Misc

Medium

85 solves

11-12

baumroll1234

Fermat's Last Theorem

Misc

Medium

83 solves

13-15

tchen

True or False 2

Misc

Hard

53 solves

16-17

tchen

List Sharing

Web

Medium

77 solves

tchen

List Sharing

Web

Medium

77 solves

18-20

tan90909090

wrong instruction

Rev

Hard

59 solves

21-23

tchen

Greetings i18n 2

Web

Hard

52 solves

24-26

tchen

Xwitter

Web

Hard

40 solves

27-28

tan90909090

Let's analyze system calls

Rev

Medium

45 solves

29-31

tchen

Springing

Web

Medium

53 solves

tchen

Springing

Web

Medium

53 solves

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for Xwitter

tchen

author

Xwitter

2026/08/29 05:39

Writeup for Let's analyze system calls

baumroll1234

Let's analyze system calls

2026/08/29 04:42

Writeup for Flag is A+B

alpha0314sub

Flag is A+B

2026/08/29 01:57

Writeup for Let's analyze system calls

mizore-fuyu

Let's analyze system calls

2026/08/28 23:24

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:

Sugoi Flag Checker

Topic: ELFReleased: Dec 12, 2025

234 solves

Rev

Hard5.0

chocorusk

USER	SOLVED AT
curetwinkle	2026/08/30 02:45
bigmc1971	2026/08/21 12:04
mightbehuman	2026/08/16 13:04
thelepi	2026/08/16 12:25
mikan1135	2026/08/16 11:52
ghostinthefingers	2026/08/08 12:00
mg7x	2026/08/02 06:30
hori	2026/07/13 01:01
rangkiasm	2026/06/26 06:31
7hep5k	2026/06/24 17:55
tadanobutubutu	2026/06/07 20:33
roaris	2026/05/31 05:31
4141414141	2026/05/26 12:56
nakamulab	2026/05/26 10:49
rito	2026/05/25 17:08
ly4	2026/05/20 12:19
suzuno	2026/05/20 12:04
famous	2026/05/13 15:07
kurokane-isumi	2026/05/09 04:53
victortrend	2026/05/08 12:12
sasarafu	2026/05/06 02:59
juck	2026/05/03 14:11
vaseline	2026/05/02 05:07
not	2026/04/29 06:01
lllllllllllllll	2026/04/24 04:40