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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
28 solves
Submissions (latest 3)
mopeneko

SOLVED!

Aug 29, 3:06 PM

tyage

SOLVED!

Aug 29, 1:34 PM

Leaderboard

Try the first challenge

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

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admin
AlpacaHack 2100
Misc
Welcome🌱
2,166 solves
Upcoming challenges reveal the , , and in advance.
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Aug 2026

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27
tchentchen
RFC100008
Web
Easy🌱
143 solves
28
2501
One More Approval
Crypto
Medium
61 solves
29
2501
zen.zip
Misc
Medium
69 solves
30
2501
Anyrunner
Misc
Medium
65 solves
31
tchentchen
Small Image Uploader 2
Web
Medium
62 solves
1
admin
Día Nacional de la Alpaca
Misc
Welcome🌱
236 solves
2
2501
Password, Please
Misc
Easy🌱
203 solves
3-4
arkark
Long Long Flag Printer 2026
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Medium
95 solves
5
pppp4649pppp4649
Happy Birthday
Crypto
Easy🌱
132 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
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13-15
tchentchen
True or False 2
Misc
Hard
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16-17
tchentchen
List Sharing
Web
Medium
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tchentchen
List Sharing
Web
Medium
77 solves
18-20
tan90909090tan90909090
wrong instruction
Rev
Hard
59 solves
21-23
tchentchen
Greetings i18n 2
Web
Hard
51 solves
24-26
tchentchen
Xwitter
Web
Hard
37 solves
27-28
tan90909090tan90909090
Let's analyze system calls
Rev
Medium
44 solves
29-31
tchentchen
Springing
Web
Medium
28 solves
 
tchentchen
Springing
Web
Medium
28 solves
1
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2
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3
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Writeups

tchen

Writeup for Xwitter

tchen

author
en
Xwitter

10 hours ago

alpha0314sub

Writeup for Flag is A+B

power

Writeup for Encoding Basics

ja

2026/08/26 12:20

power

Writeup for Bars

ja

2026/08/26 08:34

Rows:

permission denied 3

Topic: File PermissionReleased: May 7, 2026

121 solves
Misc
Medium5.5

by

minaminao

minaminao

cat: flag.txt: No such file or directory

Beginner Hint 1 (AI-translated)
  • When you connect with nc, you'll see that a shell is launched.
  • Reading chal.sh, you can see that flag.txt is created with permission 400 before the shell starts.
  • Then all files in the current directory are deleted by rm *.
  • After that, a shell is launched via sh.
  • Of course, running cat flag.txt results in No such file or directory, so you can't read the flag directly.
  • So, how can you read the flag?
Beginner Hint 2 (AI-translated)
  • flag.txt is completely gone, but it wasn't the only file that contained the flag.
  • Think about chal.sh, which also contained the flag.
permission-denied-3.tar.gz

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