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)

yahari

SOLVED!

Sep 23, 1:09 PM

sp1n0z4

SOLVED!

Sep 23, 12:34 PM

kuroiko

SOLVED!

Sep 23, 7:33 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.

Sep 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

tchen

Springing

Web

Medium

74 solves

admin

QUIZ ALPACASHOCK

Misc

Welcome🌱

127 solves

hiikunz

base 16-32-64

Misc

Easy🌱

103 solves

3-4

tan90909090

Let's Shut Down Linux

Misc

Medium

63 solves

baumroll1234

Vending Machine: Revised Version

Misc

Easy🌱

88 solves

6-8

minaminao

Bitflip RSA

Crypto

Hard

56 solves

minaminao

Bitflip RSA

Crypto

Hard

56 solves

9-11

minaminao

＼^o^／

Misc

Hard

43 solves

12-13

tan90909090

sin function vs. fsin instruction

Rev

Misc

Medium

55 solves

14-15

tan90909090

integer division

Misc

Medium

70 solves

16-18

edwowmath

neighboRhood_diStAnce

Crypto

Hard

42 solves

19-21

hiikunz

nested eval

Misc

Hard

45 solves

hiikunz

nested eval

Misc

Hard

45 solves

22-24

2501

The 3rd

Crypto

Hard

31 solves

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for nested eval

baumroll1234

nested eval

2026/09/21 23:48

Writeup for nested eval

lumma

nested eval

2026/09/21 23:42

Writeup for flag obfuscation

enesbasmaci

flag obfuscation

2026/09/21 18:32

Writeup for RFC100008

enesbasmaci

RFC100008

2026/09/21 18:31

Writeup for private method

enesbasmaci

private method

2026/09/21 18:31

Writeup for Animal Viewer

enesbasmaci

Animal Viewer

2026/09/21 18:31

Writeup for secret-table-2

enesbasmaci

secret-table-2

2026/09/21 18:30

Writeup for Vending Machine

enesbasmaci

Vending Machine

2026/09/21 18:29

Writeup for dice roll

enesbasmaci

dice roll

2026/09/21 18:28

Writeup for Flag Printer 2026

enesbasmaci

Flag Printer 2026

2026/09/21 18:28

Rows:

vuln4vuln

Topic: BOFReleased: Mar 22, 2026

111 solves

Pwn

Hard8.0

k0080