Daily AlpacaHack

A daily CTF challenge with a fun new puzzle every day

What is Daily AlpacaHack?

We publish one simple, beginner-friendly or educational CTF challenge every day!

Join Anytime

Solve within 24 hours of release 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 24 hours have passed since release.

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Today's Challenge

Submissions (latest 3)

gin

SOLVED!

Jul 21, 4:19 AM

mizore-fuyu

SOLVED!

Jul 21, 3:40 AM

shiragi

SOLVED!

Jul 21, 3:29 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.

Jul 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

tchen

Nano Services

Web

Medium

87 solves

minaminao

Super Short System Exit

Misc

Medium

82 solves

admin

Alpaca Nation

Misc

Welcome🌱

227 solves

hiikunz

Flag is A+B

Crypto

Easy🌱

137 solves

tchen

Lucky Redirect

Web

Easy🌱

129 solves

hiikunz

Renda

Rev

Medium

107 solves

tchen

IP Blocked Secret

Web

Hard

64 solves

minaminao

duplicate entry

Misc

Easy🌱

133 solves

hiikunz

Lazy RSA

Crypto

Medium

101 solves

minaminao

Let's Poly1305!

Crypto

Medium

75 solves

shiragi

private method

Misc

Easy🌱

127 solves

hiikunz

secret-table-3

Web

Medium

82 solves

baumroll1234

A slight mistake

Pwn

Hard

69 solves

tan90909090

Compile time flag checker

Rev

Hard

56 solves

baumroll1234

Redirecting to Login Page

Web

Easy🌱

136 solves

tchen

You've Got Shlex

Misc

Medium

85 solves

minaminao

Let's Poly1305! 2

Crypto

Hard

63 solves

tchen

Beat the Alpaca Lord

Web

Medium

88 solves

pppp4649

biribiri

Crypto

Medium

83 solves

tchen

Greetings CGI

Web

Hard

67 solves

hiikunz

no win func

Pwn

Hard

67 solves

tchen

Alpaca Blog

Web

Easy🌱

87 solves

tan90909090

NOP Variant

Rev

Misc

Medium

38 solves

Coming soon

minaminao

Planned topicCache

Web

Hard

tchen

Planned topicPython

Web

Hard

Coming soon

admin

Planned topicWelcome

Misc

Welcome🌱

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for Alpaca Blog

baumroll1234

Alpaca Blog

6 hours ago

Writeup for no win func

ojun

no win func

2026/07/19 15:04

Writeup for You've Got Shlex (shlex only)

kurimochi

You've Got Shlex

2026/07/19 05:58

Writeup for Greetings CGI

baumroll1234

Greetings CGI

2026/07/18 23:23

Writeup for You've Got Shlex

nitcelcius

You've Got Shlex

2026/07/18 12:59

Writeup for Compile time flag checker

edwowmath

Compile time flag checker

2026/07/18 02:07

Writeup for biribiri

baumroll1234

biribiri

2026/07/17 21:38

Writeup for Beat the Alpaca Lord

baumroll1234

Beat the Alpaca Lord

2026/07/16 21:24

Writeup for You've Got Shlex

tchen

author

You've Got Shlex

2026/07/16 01:15

Writeup for IP Blocked Secret

tchen

author

IP Blocked Secret

2026/07/15 23:53

Rows:

Alpaca Blog

Topic: GeneralReleased: Jul 20, 2026

87 solves

Web

Easy🌱4.0

tchen

USER	SOLVED AT
naaa	2 hours ago
kapumoka	10 hours ago
n0ir	13 hours ago
gonzab	13 hours ago
chara0x	13 hours ago
unubore	13 hours ago
ojun	14 hours ago
hedgehogeyexd	14 hours ago
stp	14 hours ago
naitem	15 hours ago
kumabear	15 hours ago
akasako	16 hours ago
michikusamichiya	16 hours ago
pppp4649	16 hours ago
itsuki-t	16 hours ago
baumroll1234	16 hours ago
choco	17 hours ago
happykid	17 hours ago
apender	17 hours ago
kurokane-isumi	18 hours ago
embe221ed	18 hours ago
despair09	18 hours ago
cat22222	18 hours ago
nomeaning	18 hours ago
sniperthrilla	19 hours ago