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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!

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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).

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Today's Challenge
tan90909090tan90909090
C++ flag checker
Rev
Hard
40 solves
Submissions (latest 3)
haihuiliyuyuan

SOLVED!

Jun 7, 3:25 AM

k1mq
k1mq

SOLVED!

Jun 7, 3:22 AM

nomeaning

SOLVED!

Jun 7, 3:20 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🌱
1,855 solves
Upcoming challenges reveal the , , and in advance.
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Jun 2026

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Solved
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Upcoming
Mon
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1
admin
Half-Year Recap
Misc
Welcome🌱
178 solves
2
minaminaominaminao
Cache Me If You Can
Web
Easy🌱
149 solves
3
minaminaominaminao
vm1
Misc
Medium
87 solves
4
pppp4649pppp4649
Small e
Crypto
Easy🌱
95 solves
5
minaminaominaminao
RPS GAME
Misc
Crypto
Medium
79 solves
6
nozokare
Flag for localhost
Web
Easy🌱
92 solves
7
tan90909090tan90909090
C++ flag checker
Rev
Hard
40 solves
8
shiragishiragi
Planned topicNetwork
Misc
Easy🌱
9
Coming soon
10
shiragishiragi
Planned topicFile Permission
Misc
Medium
11
Coming soon
12
Coming soon
13
pppp4649pppp4649
Planned topicElliptic Curve
Crypto
Medium
14
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15
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16
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17
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18
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21
k0080k0080
Planned topicHeap
Pwn
Hard
22
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23
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24
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25
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26
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27
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28
pppp4649pppp4649
Planned topicTBA
Pwn
Hard
29
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30
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1
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2
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3
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4
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5
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Writeup for RPS GAME

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Writeup for RPS GAME

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Writeup for Small e

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Writeup for RPS GAME

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Rows:

Rate My Alpaca

Topic: File UploadReleased: Apr 22, 2026

97 solves
Web
Medium

by

tchen

tchen

How nice is your alpaca?

Beginner Hint
  • What kind of input can you use for $filename?
  • To fully control the input above, you may need to use an HTTP client other than a browser.
    • For methods of sending data without using a browser, refer to my writeup for I Wanna Be the Admin.
rate-my-alpaca.tar.gz

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