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.

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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)

infernosalex

SOLVED!

Feb 16, 8:33 PM

cyanos

SOLVED!

Feb 16, 7:46 PM

m200is

SOLVED!

Feb 16, 5:42 PM

Leaderboard

Period

Try the first challenge

Is this your first CTF? Let's begin by tackling the first challenge released on Daily AlpacaHack.

Topics and categories are revealed in advance for upcoming challenges.

Feb 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

keymoon

git gc

Misc

Medium

139 solves

chocorusk

ToyPQC

Crypto

Hard

100 solves

tchen

No JS

Web

Medium

116 solves

k0080

shellcode-101

Pwn

Medium

117 solves

yu212

Linear Coffee Generator

Crypto

Hard

105 solves

ark

optimal-sort

Misc

Hard

94 solves

admin

Camelidae

Misc

Welcome

270 solves

minaminao

Substance

Crypto

Easy

186 solves

tan90909090

read-a-binary

Rev

Easy

170 solves

tchen

Magic Engine

Web

Easy

190 solves

kanon

RRe_Time_Limiter

Crypto

Medium

144 solves

minaminao

The World

Misc

Easy

142 solves

tan90909090

misdirection

Rev

Medium

121 solves

hiikunz

Compressor

Misc

Hard

91 solves

tchen

Plz Login

Web

Medium

160 solves

k0080

Alpaca-Llama Ranch

Pwn

Hard

102 solves

ark

destructuring

Misc

Easy

114 solves

hiikunz

AAAAAAAAEEEEEEEESSSSSSSS

Crypto

Medium

98 solves

minaminao

nc magic

Misc

Medium

107 solves

hiikunz

simple ROP

Pwn

Hard

86 solves

tchen

You are being redirected

Web

Medium

78 solves

kakur41

Alpaillier

Crypto

Medium

96 solves

rsk0315

wages of sin()

Rev

Misc

Hard

31 solves

k0080

Planned topicOptimization

Pwn

Medium

minaminao

Planned topicDeserialization

Misc

Medium

rsk0315

Planned topicControl Sequences

Misc

Rev

Medium

pppp4649

Planned topicRSA

Crypto

Hard

k0080

Planned topicUninitialized Memory

Pwn

Hard

Coming soon

Go to B-SIDE

Writeups

Writeup for Alpaillier goroshirow ja Alpaillier 5 hours ago
Writeup for simple ROP goroshirow ja simple ROP yesterday
Writeup for simple ROP rsk0315 ja simple ROP yesterday
Writeup for shellcode-101 rsk0315 ja shellcode-101 2 days ago
Writeup for Daily AlpacaHack 2/8-2/14 kakur41 ja AAAAAAAAEEEEEEEESSSSSSSS +6 2 days ago
【脆弱】Daily AlpacaHackを作問者の前で解いてみた！ I wanna be the Admin【t-chen】 asusn ja I wanna be the Admin 2 days ago
Writeup for nc magic goroshirow ja nc magic 3 days ago
Writeup for AAAAAAAAEEEEEEEESSSSSSSS goroshirow ja AAAAAAAAEEEEEEEESSSSSSSS 4 days ago
Writeup for destructuring rsk0315 ja destructuring 4 days ago
Writeup for destructuring itsuki-t ja destructuring 4 days ago

Rows:

read-a-binary

Topic: ELF

170 solves

Rev

Easy

Author:

tan90909090

🦙 < Let's try reading what the ELF binary does!

Beginner Hint

This challenge is in the Rev (Reverse Engineering) category.
Flag checkers are a common theme in Rev problems.
A flag checker executable or script accepts player input and tells you whether it matches the flag.
The provided file is the ELF binary read-a-binary.
The goal is to find an input (the flag) that makes the binary print Correct! by analyzing the binary.
There are a variety of tools available that can analyze ELF binaries.
Some tools can show a higher level of representations than others.

read-a-binary

description solves writeups