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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!

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Solve each challenge within its time window to appear on the leaderboard.

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Today's Challenge
tchentchen
Springing
Web
Medium
40 solves
Submissions (latest 3)
claw88

SOLVED!

Aug 30, 11:44 AM

shiragi

SOLVED!

Aug 30, 7:35 AM

Leaderboard

Try the first challenge

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

View challenge
admin
AlpacaHack 2100
Misc
Welcome🌱
2,167 solves
Upcoming challenges reveal the , , and in advance.
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Aug 2026

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27
tchentchen
RFC100008
Web
Easy🌱
144 solves
28
2501
One More Approval
Crypto
Medium
61 solves
29
2501
zen.zip
Misc
Medium
69 solves
30
2501
Anyrunner
Misc
Medium
66 solves
31
tchentchen
Small Image Uploader 2
Web
Medium
63 solves
1
admin
Día Nacional de la Alpaca
Misc
Welcome🌱
237 solves
2
2501
Password, Please
Misc
Easy🌱
204 solves
3-4
arkark
Long Long Flag Printer 2026
Misc
Medium
95 solves
5
pppp4649pppp4649
Happy Birthday
Crypto
Easy🌱
134 solves
6-8
hiikunzhiikunz
AESAESAESAESAESAES
Crypto
Hard
60 solves
9-10
tchentchen
Not so Pyf**k
Misc
Medium
84 solves
 
tchentchen
Not so Pyf**k
Misc
Medium
84 solves
11-12
baumroll1234
Fermat's Last Theorem
Misc
Medium
82 solves
13-15
tchentchen
True or False 2
Misc
Hard
53 solves
16-17
tchentchen
List Sharing
Web
Medium
77 solves
 
tchentchen
List Sharing
Web
Medium
77 solves
18-20
tan90909090tan90909090
wrong instruction
Rev
Hard
59 solves
21-23
tchentchen
Greetings i18n 2
Web
Hard
52 solves
24-26
tchentchen
Xwitter
Web
Hard
40 solves
27-28
tan90909090tan90909090
Let's analyze system calls
Rev
Medium
44 solves
29-31
tchentchen
Springing
Web
Medium
40 solves
 
tchentchen
Springing
Web
Medium
40 solves
1
Coming soon
2
Coming soon
3
Coming soon
4
Coming soon
5
Coming soon
6
Coming soon

Want a harder challenge?

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Writeups

tchen

Writeup for Xwitter

tchen

author
en
Xwitter

2026/08/29 05:39

alpha0314sub

Writeup for Flag is A+B

ja

2026/08/29 01:57

power

Writeup for Encoding Basics

ja

2026/08/26 12:20

power

Writeup for Bars

ja

2026/08/26 08:34

Rows:

Greetings CGI

Topic: CGIReleased: Jul 18, 2026

73 solves
Web
Hard6.0

by

tchen

tchen

I'm bringing CGI back from the old days!

Beginner Hint: About the Admin Bot
  • In this challenge, you are given not only the web application itself, but also an admin bot.
  • The admin bot has a cookie containing the flag, and it opens a specified path using Headless Chrome.
  • Therefore, your goal is to make the admin bot trigger your payload and send the cookie value to an external server.
  • You can prepare your own server as the destination, or use an existing service that lets you receive and inspect HTTP requests.
  • If you are still not familiar with how to use the admin bot or how to inspect incoming requests, it may help to first solve Fushigi Crawler and read its writeup.
greetings-cgi.tar.gz

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