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)

sota70

SOLVED!

Aug 30, 12:14 PM

claw88

SOLVED!

Aug 30, 11:44 AM

labpump

SOLVED!

Aug 30, 7:56 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🌱

144 solves

2501

One More Approval

Crypto

Medium

61 solves

2501

zen.zip

Misc

Medium

69 solves

2501

Anyrunner

Misc

Medium

66 solves

tchen

Small Image Uploader 2

Web

Medium

63 solves

admin

Día Nacional de la Alpaca

Misc

Welcome🌱

238 solves

2501

Password, Please

Misc

Easy🌱

204 solves

3-4

ark

Long Long Flag Printer 2026

Misc

Medium

95 solves

pppp4649

Happy Birthday

Crypto

Easy🌱

135 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

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

44 solves

29-31

tchen

Springing

Web

Medium

41 solves

tchen

Springing

Web

Medium

41 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:

Beat the Alpaca Lord

Topic: JSONReleased: Jul 16, 2026

100 solves

Web

Medium5.0

tchen

USER	SOLVED AT
curetwinkle	2026/08/29 12:02
ryuun1corn	2026/08/26 08:38
reomin	2026/08/15 15:31
hiro2620	2026/08/12 15:47
4141414141	2026/08/12 15:08
ctf-udon	2026/08/12 05:28
shogo-mk2	2026/08/11 15:30
madics	2026/08/09 03:58
chara0x	2026/08/03 14:09
404gh0st	2026/07/26 13:55
guren	2026/07/23 22:25
unity	2026/07/22 12:36
kooooochi	2026/07/20 12:39
gauleopia	2026/07/19 04:59
naaa	2026/07/18 08:56
apender	2026/07/18 00:42
turty	2026/07/17 17:53
n0ir	2026/07/17 13:19
kikkin	2026/07/17 11:08
nanashiku	2026/07/17 10:00
gattoartz	2026/07/17 09:09
cac	2026/07/17 04:07
aiueo6614	2026/07/17 02:54
nakamulab	2026/07/17 01:54
despair09	2026/07/16 16:23