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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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Today's Challenge
shiragishiragi
AlpacaForm
Rev
Medium
49 solves
Submissions (latest 3)
toto1010orange

SOLVED!

May 28, 6:49 AM

kowerkoint

SOLVED!

May 28, 5:07 AM

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🌱
1,825 solves
Upcoming challenges reveal the , , and in advance.
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May 2026

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27
shiragishiragi
Unrevealed TXT
Misc
Easy🌱
129 solves
28
seriotonserioton
unheard
Misc
Medium
78 solves
29
minaminaominaminao
permission denied
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Hard
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30
minaminaominaminao
permission denied 2
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Medium
83 solves
1
admin
Alpaca++
Misc
Welcome🌱
261 solves
2
tchentchen
Alpaca Rangers 2
Web
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220 solves
3
pppp4649pppp4649
Small N
Crypto
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157 solves
4
hiikunzhiikunz
secret-table-2
Web
Medium
146 solves
5
seriotonserioton
do the math
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Medium
116 solves
6
trimscashtrimscash
func-array
Pwn
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153 solves
7
minaminaominaminao
permission denied 3
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Medium
116 solves
8
baumroll1234
Vending Machine
Misc
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179 solves
9
hiikunzhiikunz
reused n
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117 solves
10
rsk0315
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11
seriotonserioton
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12
minaminaominaminao
hidden service
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13
tchentchen
Super Short Python Golf
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14
minaminaominaminao
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15
tan90909090tan90909090
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16
k0080k0080
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17
tan90909090tan90909090
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shiragishiragi
Flag for Switch
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167 solves
19
pppp4649pppp4649
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tchentchen
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kakur41kakur41
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22
nozokare
Time Travelers' OTP
Web
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23
minaminaominaminao
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k0080k0080
25
minaminaominaminao
Catrunner
Misc
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101 solves
26
baumroll1234
I cannot decrypt RSA
Crypto
Medium
82 solves
27
tchentchen
Hello Programmer!
Web
Medium
68 solves
28
shiragishiragi
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pppp4649pppp4649
Planned topicRSA
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Medium
31
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Writeups

Writeup for Hello Programmer!

aiueo6614

ja
Hello Programmer!

3 hours ago

tadanobutubutu

Writeup for Hello Programmer!

Daily AlpacaHackに挑戦するつくよみちゃん 05/27/Hello Programmer!/tchen

Writeup for I cannot decrypt RSA

author
ja

18 hours ago

tadanobutubutu

Writeup for I cannot decrypt RSA

Rows:

Another Login Challenge

Topic: LoginReleased: Mar 13, 2026

140 solves
Web
Medium

by

tchen

tchen

Login, login, and login!

Beginner Hint 1 (AI-translated)
  • In index.js, a simple login feature is implemented.

  • It appears to check that users[username] exists and that users[username].password matches the provided password.

  • It doesn’t seem possible to create your own user. Also, a user called admin is registered, but guessing that password would be impossible.

Beginner Hint 2 (AI-translated)
  • In JavaScript, users["foobar"] and users.foobar are almost equivalent. Could this be used somehow?
  • The login form alone might not allow you to send the intended data. For methods of sending data without using a browser, refer to my writeup for I wanna be the Admin.
another-login-challenge.tar.gz

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