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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
Xwitter
Web
Hard
21 solves
Submissions (latest 3)
koufu193
koufu193

SOLVED!

Aug 25, 4:42 AM

hiikunz

SOLVED!

Aug 24, 4:59 PM

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🌱
2,151 solves
Upcoming challenges reveal the , , and in advance.
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Aug 2026

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27
tchentchen
RFC100008
Web
Easy🌱
142 solves
28
2501
One More Approval
Crypto
Medium
61 solves
29
2501
zen.zip
Misc
Medium
68 solves
30
2501
Anyrunner
Misc
Medium
60 solves
31
tchentchen
Small Image Uploader 2
Web
Medium
61 solves
1
admin
Día Nacional de la Alpaca
Misc
Welcome🌱
218 solves
2
2501
Password, Please
Misc
Easy🌱
180 solves
3-4
arkark
Long Long Flag Printer 2026
Misc
Medium
93 solves
5
pppp4649pppp4649
Happy Birthday
Crypto
Easy🌱
121 solves
6-8
hiikunzhiikunz
AESAESAESAESAESAES
Crypto
Hard
59 solves
9-10
tchentchen
Not so Pyf**k
Misc
Medium
81 solves
 
tchentchen
Not so Pyf**k
Misc
Medium
81 solves
11-12
baumroll1234
Fermat's Last Theorem
Misc
Medium
79 solves
13-15
tchentchen
True or False 2
Misc
Hard
52 solves
16-17
tchentchen
List Sharing
Web
Medium
71 solves
 
tchentchen
List Sharing
Web
Medium
71 solves
18-20
tan90909090tan90909090
wrong instruction
Rev
Hard
57 solves
21-23
tchentchen
Greetings i18n 2
Web
Hard
47 solves
24-26
tchentchen
Xwitter
Web
Hard
21 solves
27
Coming soon
28
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29
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30
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31
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1
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2
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Writeups

Writeup for wrong instruction

umineko

ja
wrong instruction

2026/08/22 05:08

power

Writeup for Leaked Flag Checker

ja

2026/08/18 11:53

power

Writeup for Password, Please

ja

2026/08/18 03:26

Rows:

duplicate entry

Topic: ZIPReleased: Jul 6, 2026

176 solves
Misc
Easy🌱1.5

by

minaminao

minaminao

You won't get the real flag.txt even after extraction! Probably.

Beginner Hint
  • If you read make_zip.py, you can see that many flag.txt entries are created.
  • When you extract flag.zip, depending on the tool, you may get two files, such as README.md and flag.txt.
  • Even if you look at this flag.txt, it only says No flag here. Try harder.
  • This is because the flag.txt containing the flag can be overwritten or ignored due to duplicate entries.
duplicate-entry.tar.gz

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