Practice arena

CTF Arena — 300 free challenges

Standalone CTF puzzles — separate from Academy Labs. Each challenge includes steps to recover the flag. Beginner · Intermediate · Expert. Submit CYBERLIUM{...} for XP. For live vulnerable apps, use Labs.Sign in so XP lands on your account.

How to solve a CTF challenge

1
Sign in
Log in to earn XP. You can still read challenges while signed out.
2
CTF ≠ Labs
Academy Labs are live vulnerable apps under Labs. CTF challenges are separate self-contained puzzles — they do not open lab sandboxes.
3
Open a CTF challenge
Pick Beginner / Intermediate / Expert, then open a card.
4
Follow “How to get the flag”
Each challenge includes step-by-step solve instructions (decode, search logs, join strings, etc.).
5
Submit CYBERLIUM{...}
Paste the recovered flag and Submit. Correct = XP. Wrong = try again.

Crypto·Beginner100 XP
ROT13 Memo #1
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_001} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Beginner100 XP
Caesar Shift-5 #2
Ciphertext (Caesar +5): HDGJWQNZR{hwduyt_ufhp_002} Shift letters back by 5. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +5.
2. Decode by shifting each letter back by 5 (or forward by 21).
3. +2 more steps inside →
Crypto·Beginner100 XP
Hex Dump #3
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3030337d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Beginner100 XP
XOR Key 0x24 #4
Each byte XOR'd with 0x24: 677d666176686d71695f47565d54504b7b5445474f7b14141059 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x24.
3. +2 more steps inside →
Crypto·Beginner100 XP
Base64 Packet #5
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzAwNX0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Beginner100 XP
ROT13 Memo #6
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_006} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Beginner100 XP
Caesar Shift-10 #7
Ciphertext (Caesar +10): MILOBVSEW{mbizdy_zkmu_007} Shift letters back by 10. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +10.
2. Decode by shifting each letter back by 10 (or forward by 16).
3. +2 more steps inside →
Crypto·Beginner100 XP
Hex Dump #8
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3030387d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Beginner100 XP
XOR Key 0x29 #9
Each byte XOR'd with 0x29: 6a706b6c7b65607c64524a5b50595d467659484a427619191054 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x29.
3. +2 more steps inside →
Crypto·Beginner100 XP
Base64 Packet #10
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzAxMH0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Beginner100 XP
ROT13 Memo #11
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_011} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Beginner100 XP
Caesar Shift-5 #12
Ciphertext (Caesar +5): HDGJWQNZR{hwduyt_ufhp_012} Shift letters back by 5. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +5.
2. Decode by shifting each letter back by 5 (or forward by 21).
3. +2 more steps inside →
Crypto·Beginner100 XP
Hex Dump #13
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3031337d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Beginner100 XP
XOR Key 0x2e #14
Each byte XOR'd with 0x2e: 6d776c6b7c62677b63554d5c575e5a41715e4f4d45711e1f1a53 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x2e.
3. +2 more steps inside →
Crypto·Beginner100 XP
Base64 Packet #15
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzAxNX0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Beginner100 XP
ROT13 Memo #16
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_016} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Beginner100 XP
Caesar Shift-10 #17
Ciphertext (Caesar +10): MILOBVSEW{mbizdy_zkmu_017} Shift letters back by 10. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +10.
2. Decode by shifting each letter back by 10 (or forward by 16).
3. +2 more steps inside →
Crypto·Beginner100 XP
Hex Dump #18
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3031387d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Beginner100 XP
XOR Key 0x33 #19
Each byte XOR'd with 0x33: 706a7176617f7a667e4850414a43475c6c435250586c03020a4e Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x33.
3. +2 more steps inside →
Crypto·Beginner100 XP
Base64 Packet #20
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzAyMH0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Beginner100 XP
ROT13 Memo #21
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_021} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Beginner100 XP
Caesar Shift-5 #22
Ciphertext (Caesar +5): HDGJWQNZR{hwduyt_ufhp_022} Shift letters back by 5. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +5.
2. Decode by shifting each letter back by 5 (or forward by 21).
3. +2 more steps inside →
Crypto·Beginner100 XP
Hex Dump #23
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3032337d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Beginner100 XP
XOR Key 0x38 #24
Each byte XOR'd with 0x38: 7b617a7d6a74716d75435b4a41484c576748595b5367080a0c45 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x38.
3. +2 more steps inside →
Crypto·Beginner100 XP
Base64 Packet #25
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzAyNX0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Beginner100 XP
ROT13 Memo #26
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_026} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Beginner100 XP
Caesar Shift-10 #27
Ciphertext (Caesar +10): MILOBVSEW{mbizdy_zkmu_027} Shift letters back by 10. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +10.
2. Decode by shifting each letter back by 10 (or forward by 16).
3. +2 more steps inside →
Crypto·Beginner100 XP
Hex Dump #28
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3032387d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Beginner100 XP
XOR Key 0x3d #29
Each byte XOR'd with 0x3d: 7e647f786f71746870465e4f444d4952624d5c5e56620d0f0440 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x3d.
3. +2 more steps inside →
Crypto·Beginner100 XP
Base64 Packet #30
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzAzMH0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Beginner100 XP
ROT13 Memo #31
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_031} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Beginner100 XP
Caesar Shift-5 #32
Ciphertext (Caesar +5): HDGJWQNZR{hwduyt_ufhp_032} Shift letters back by 5. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +5.
2. Decode by shifting each letter back by 5 (or forward by 21).
3. +2 more steps inside →
Crypto·Intermediate200 XP
Hex Dump #33
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3033337d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Intermediate200 XP
XOR Key 0x42 #34
Each byte XOR'd with 0x42: 011b0007100e0b170f3921303b32362d1d322321291d7271763f Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x42.
3. +2 more steps inside →
Crypto·Intermediate200 XP
Base64 Packet #35
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzAzNX0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Intermediate200 XP
ROT13 Memo #36
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_036} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Intermediate200 XP
Caesar Shift-10 #37
Ciphertext (Caesar +10): MILOBVSEW{mbizdy_zkmu_037} Shift letters back by 10. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +10.
2. Decode by shifting each letter back by 10 (or forward by 16).
3. +2 more steps inside →
Crypto·Intermediate200 XP
Hex Dump #38
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3033387d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Intermediate200 XP
XOR Key 0x47 #39
Each byte XOR'd with 0x47: 041e0502150b0e120a3c24353e373328183726242c1877747e3a Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x47.
3. +2 more steps inside →
Crypto·Intermediate200 XP
Base64 Packet #40
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzA0MH0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Intermediate200 XP
ROT13 Memo #41
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_041} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Intermediate200 XP
Caesar Shift-5 #42
Ciphertext (Caesar +5): HDGJWQNZR{hwduyt_ufhp_042} Shift letters back by 5. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +5.
2. Decode by shifting each letter back by 5 (or forward by 21).
3. +2 more steps inside →
Crypto·Intermediate200 XP
Hex Dump #43
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3034337d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Intermediate200 XP
XOR Key 0x24 #44
Each byte XOR'd with 0x24: 677d666176686d71695f47565d54504b7b5445474f7b14101059 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x24.
3. +2 more steps inside →
Crypto·Intermediate200 XP
Base64 Packet #45
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzA0NX0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Intermediate200 XP
ROT13 Memo #46
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_046} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Intermediate200 XP
Caesar Shift-10 #47
Ciphertext (Caesar +10): MILOBVSEW{mbizdy_zkmu_047} Shift letters back by 10. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +10.
2. Decode by shifting each letter back by 10 (or forward by 16).
3. +2 more steps inside →
Crypto·Intermediate200 XP
Hex Dump #48
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3034387d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Intermediate200 XP
XOR Key 0x29 #49
Each byte XOR'd with 0x29: 6a706b6c7b65607c64524a5b50595d467659484a4276191d1054 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x29.
3. +2 more steps inside →
Crypto·Intermediate200 XP
Base64 Packet #50
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzA1MH0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Intermediate200 XP
ROT13 Memo #51
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_051} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Intermediate200 XP
Caesar Shift-5 #52
Ciphertext (Caesar +5): HDGJWQNZR{hwduyt_ufhp_052} Shift letters back by 5. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +5.
2. Decode by shifting each letter back by 5 (or forward by 21).
3. +2 more steps inside →
Crypto·Intermediate200 XP
Hex Dump #53
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3035337d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Intermediate200 XP
XOR Key 0x2e #54
Each byte XOR'd with 0x2e: 6d776c6b7c62677b63554d5c575e5a41715e4f4d45711e1b1a53 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x2e.
3. +2 more steps inside →
Crypto·Intermediate200 XP
Base64 Packet #55
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzA1NX0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Intermediate200 XP
ROT13 Memo #56
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_056} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Intermediate200 XP
Caesar Shift-10 #57
Ciphertext (Caesar +10): MILOBVSEW{mbizdy_zkmu_057} Shift letters back by 10. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +10.
2. Decode by shifting each letter back by 10 (or forward by 16).
3. +2 more steps inside →
Crypto·Intermediate200 XP
Hex Dump #58
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3035387d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Intermediate200 XP
XOR Key 0x33 #59
Each byte XOR'd with 0x33: 706a7176617f7a667e4850414a43475c6c435250586c03060a4e Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x33.
3. +2 more steps inside →
Crypto·Intermediate200 XP
Base64 Packet #60
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzA2MH0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Intermediate200 XP
ROT13 Memo #61
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_061} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Intermediate200 XP
Caesar Shift-5 #62
Ciphertext (Caesar +5): HDGJWQNZR{hwduyt_ufhp_062} Shift letters back by 5. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +5.
2. Decode by shifting each letter back by 5 (or forward by 21).
3. +2 more steps inside →
Crypto·Intermediate200 XP
Hex Dump #63
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3036337d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Intermediate200 XP
XOR Key 0x38 #64
Each byte XOR'd with 0x38: 7b617a7d6a74716d75435b4a41484c576748595b5367080e0c45 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x38.
3. +2 more steps inside →
Crypto·Expert300 XP
Base64 Packet #65
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzA2NX0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Expert300 XP
ROT13 Memo #66
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_066} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Expert300 XP
Caesar Shift-10 #67
Ciphertext (Caesar +10): MILOBVSEW{mbizdy_zkmu_067} Shift letters back by 10. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +10.
2. Decode by shifting each letter back by 10 (or forward by 16).
3. +2 more steps inside →
Crypto·Expert300 XP
Hex Dump #68
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3036387d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Expert300 XP
XOR Key 0x3d #69
Each byte XOR'd with 0x3d: 7e647f786f71746870465e4f444d4952624d5c5e56620d0b0440 Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x3d.
3. +2 more steps inside →
Crypto·Expert300 XP
Base64 Packet #70
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzA3MH0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Expert300 XP
ROT13 Memo #71
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_071} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Expert300 XP
Caesar Shift-5 #72
Ciphertext (Caesar +5): HDGJWQNZR{hwduyt_ufhp_072} Shift letters back by 5. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +5.
2. Decode by shifting each letter back by 5 (or forward by 21).
3. +2 more steps inside →
Crypto·Expert300 XP
Hex Dump #73
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3037337d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Expert300 XP
XOR Key 0x42 #74
Each byte XOR'd with 0x42: 011b0007100e0b170f3921303b32362d1d322321291d7275763f Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x42.
3. +2 more steps inside →
Crypto·Expert300 XP
Base64 Packet #75
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzA3NX0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Crypto·Expert300 XP
ROT13 Memo #76
Ops memo obfuscated with ROT13: PLOREYVHZ{pelcgb_cnpx_076} Recover the plaintext flag. CTF only — separate from Labs.
How to get the flag
1. Copy the ROT13 ciphertext.
2. Apply ROT13 again (it is symmetric) using CyberChef or: tr 'A-Za-z' 'N-ZA-Mn-za-m'
3. +2 more steps inside →
Crypto·Expert300 XP
Caesar Shift-10 #77
Ciphertext (Caesar +10): MILOBVSEW{mbizdy_zkmu_077} Shift letters back by 10. Digits and symbols stay. CTF puzzle (not a Lab).
How to get the flag
1. Treat A–Z / a–z as a Caesar cipher with shift +10.
2. Decode by shifting each letter back by 10 (or forward by 16).
3. +2 more steps inside →
Crypto·Expert300 XP
Hex Dump #78
Hex-encoded flag: 43594245524c49554d7b63727970746f5f7061636b5f3037387d Convert hex → ASCII. CTF challenge — Labs are unrelated.
How to get the flag
1. Copy the hex string (even length).
2. Decode: xxd -r -p or python -c "print(bytes.fromhex('...').decode())"
3. +2 more steps inside →
Crypto·Expert300 XP
XOR Key 0x47 #79
Each byte XOR'd with 0x47: 041e0502150b0e120a3c24353e373328183726242c1877707e3a Recover plaintext. Standalone CTF — not linked to Labs.
How to get the flag
1. Parse the hex into bytes.
2. XOR every byte with 0x47.
3. +2 more steps inside →
Crypto·Expert300 XP
Base64 Packet #80
A captured token is Base64-encoded: Q1lCRVJMSVVNe2NyeXB0b19wYWNrXzA4MH0= Decode it to recover the CTF flag. This is a CTF puzzle — not an Academy Lab.
How to get the flag
1. Copy the Base64 string from the problem statement.
2. Decode with: echo '<string>' | base64 -d (Cloud Shell / Linux) or an online Base64 decoder.
3. +2 more steps inside →
Forensics·Beginner100 XP
HTTP Header Trace #1
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMDF9 Cookie: sid=1abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Beginner100 XP
Strings Excerpt #2
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_2 FLAG_CANDIDATE=CYBERLIUM{forensics_002} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Beginner100 XP
Auth Log Slice #3
Practice auth log (fictional): 2026-07-01T10:00:03Z FAIL user=guest 2026-07-01T10:00:13Z OK user=admin note=CYBERLIUM{forensics_003} 2026-07-01T10:00:23Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Beginner100 XP
HTTP Header Trace #4
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMDR9 Cookie: sid=4abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Beginner100 XP
Strings Excerpt #5
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_5 FLAG_CANDIDATE=CYBERLIUM{forensics_005} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Beginner100 XP
Auth Log Slice #6
Practice auth log (fictional): 2026-07-01T10:00:06Z FAIL user=guest 2026-07-01T10:00:16Z OK user=admin note=CYBERLIUM{forensics_006} 2026-07-01T10:00:26Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Beginner100 XP
HTTP Header Trace #7
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMDd9 Cookie: sid=7abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Beginner100 XP
Strings Excerpt #8
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_8 FLAG_CANDIDATE=CYBERLIUM{forensics_008} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Beginner100 XP
Auth Log Slice #9
Practice auth log (fictional): 2026-07-01T10:00:00Z FAIL user=guest 2026-07-01T10:00:10Z OK user=admin note=CYBERLIUM{forensics_009} 2026-07-01T10:00:20Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Beginner100 XP
HTTP Header Trace #10
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMTB9 Cookie: sid=10abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Beginner100 XP
Strings Excerpt #11
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_11 FLAG_CANDIDATE=CYBERLIUM{forensics_011} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Beginner100 XP
Auth Log Slice #12
Practice auth log (fictional): 2026-07-01T10:00:03Z FAIL user=guest 2026-07-01T10:00:13Z OK user=admin note=CYBERLIUM{forensics_012} 2026-07-01T10:00:23Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Beginner100 XP
HTTP Header Trace #13
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMTN9 Cookie: sid=13abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Beginner100 XP
Strings Excerpt #14
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_14 FLAG_CANDIDATE=CYBERLIUM{forensics_014} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Beginner100 XP
Auth Log Slice #15
Practice auth log (fictional): 2026-07-01T10:00:06Z FAIL user=guest 2026-07-01T10:00:16Z OK user=admin note=CYBERLIUM{forensics_015} 2026-07-01T10:00:26Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Beginner100 XP
HTTP Header Trace #16
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMTZ9 Cookie: sid=16abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Beginner100 XP
Strings Excerpt #17
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_17 FLAG_CANDIDATE=CYBERLIUM{forensics_017} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Beginner100 XP
Auth Log Slice #18
Practice auth log (fictional): 2026-07-01T10:00:00Z FAIL user=guest 2026-07-01T10:00:10Z OK user=admin note=CYBERLIUM{forensics_018} 2026-07-01T10:00:20Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Beginner100 XP
HTTP Header Trace #19
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMTl9 Cookie: sid=19abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Beginner100 XP
Strings Excerpt #20
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_20 FLAG_CANDIDATE=CYBERLIUM{forensics_020} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Beginner100 XP
Auth Log Slice #21
Practice auth log (fictional): 2026-07-01T10:00:03Z FAIL user=guest 2026-07-01T10:00:13Z OK user=admin note=CYBERLIUM{forensics_021} 2026-07-01T10:00:23Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Beginner100 XP
HTTP Header Trace #22
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMjJ9 Cookie: sid=22abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Beginner100 XP
Strings Excerpt #23
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_23 FLAG_CANDIDATE=CYBERLIUM{forensics_023} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Beginner100 XP
Auth Log Slice #24
Practice auth log (fictional): 2026-07-01T10:00:06Z FAIL user=guest 2026-07-01T10:00:16Z OK user=admin note=CYBERLIUM{forensics_024} 2026-07-01T10:00:26Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Intermediate200 XP
HTTP Header Trace #25
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMjV9 Cookie: sid=25abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Intermediate200 XP
Strings Excerpt #26
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_26 FLAG_CANDIDATE=CYBERLIUM{forensics_026} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Intermediate200 XP
Auth Log Slice #27
Practice auth log (fictional): 2026-07-01T10:00:00Z FAIL user=guest 2026-07-01T10:00:10Z OK user=admin note=CYBERLIUM{forensics_027} 2026-07-01T10:00:20Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Intermediate200 XP
HTTP Header Trace #28
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMjh9 Cookie: sid=28abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Intermediate200 XP
Strings Excerpt #29
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_29 FLAG_CANDIDATE=CYBERLIUM{forensics_029} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Intermediate200 XP
Auth Log Slice #30
Practice auth log (fictional): 2026-07-01T10:00:03Z FAIL user=guest 2026-07-01T10:00:13Z OK user=admin note=CYBERLIUM{forensics_030} 2026-07-01T10:00:23Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Intermediate200 XP
HTTP Header Trace #31
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMzF9 Cookie: sid=31abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Intermediate200 XP
Strings Excerpt #32
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_32 FLAG_CANDIDATE=CYBERLIUM{forensics_032} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Intermediate200 XP
Auth Log Slice #33
Practice auth log (fictional): 2026-07-01T10:00:06Z FAIL user=guest 2026-07-01T10:00:16Z OK user=admin note=CYBERLIUM{forensics_033} 2026-07-01T10:00:26Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Intermediate200 XP
HTTP Header Trace #34
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMzR9 Cookie: sid=34abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Intermediate200 XP
Strings Excerpt #35
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_35 FLAG_CANDIDATE=CYBERLIUM{forensics_035} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Intermediate200 XP
Auth Log Slice #36
Practice auth log (fictional): 2026-07-01T10:00:00Z FAIL user=guest 2026-07-01T10:00:10Z OK user=admin note=CYBERLIUM{forensics_036} 2026-07-01T10:00:20Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Intermediate200 XP
HTTP Header Trace #37
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wMzd9 Cookie: sid=37abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Intermediate200 XP
Strings Excerpt #38
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_38 FLAG_CANDIDATE=CYBERLIUM{forensics_038} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Intermediate200 XP
Auth Log Slice #39
Practice auth log (fictional): 2026-07-01T10:00:03Z FAIL user=guest 2026-07-01T10:00:13Z OK user=admin note=CYBERLIUM{forensics_039} 2026-07-01T10:00:23Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Intermediate200 XP
HTTP Header Trace #40
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wNDB9 Cookie: sid=40abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Intermediate200 XP
Strings Excerpt #41
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_41 FLAG_CANDIDATE=CYBERLIUM{forensics_041} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Intermediate200 XP
Auth Log Slice #42
Practice auth log (fictional): 2026-07-01T10:00:06Z FAIL user=guest 2026-07-01T10:00:16Z OK user=admin note=CYBERLIUM{forensics_042} 2026-07-01T10:00:26Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Intermediate200 XP
HTTP Header Trace #43
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wNDN9 Cookie: sid=43abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Intermediate200 XP
Strings Excerpt #44
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_44 FLAG_CANDIDATE=CYBERLIUM{forensics_044} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Intermediate200 XP
Auth Log Slice #45
Practice auth log (fictional): 2026-07-01T10:00:00Z FAIL user=guest 2026-07-01T10:00:10Z OK user=admin note=CYBERLIUM{forensics_045} 2026-07-01T10:00:20Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Intermediate200 XP
HTTP Header Trace #46
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wNDZ9 Cookie: sid=46abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Intermediate200 XP
Strings Excerpt #47
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_47 FLAG_CANDIDATE=CYBERLIUM{forensics_047} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Intermediate200 XP
Auth Log Slice #48
Practice auth log (fictional): 2026-07-01T10:00:03Z FAIL user=guest 2026-07-01T10:00:13Z OK user=admin note=CYBERLIUM{forensics_048} 2026-07-01T10:00:23Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Expert300 XP
HTTP Header Trace #49
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wNDl9 Cookie: sid=49abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Expert300 XP
Strings Excerpt #50
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_50 FLAG_CANDIDATE=CYBERLIUM{forensics_050} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Expert300 XP
Auth Log Slice #51
Practice auth log (fictional): 2026-07-01T10:00:06Z FAIL user=guest 2026-07-01T10:00:16Z OK user=admin note=CYBERLIUM{forensics_051} 2026-07-01T10:00:26Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Expert300 XP
HTTP Header Trace #52
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wNTJ9 Cookie: sid=52abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Expert300 XP
Strings Excerpt #53
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_53 FLAG_CANDIDATE=CYBERLIUM{forensics_053} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Expert300 XP
Auth Log Slice #54
Practice auth log (fictional): 2026-07-01T10:00:00Z FAIL user=guest 2026-07-01T10:00:10Z OK user=admin note=CYBERLIUM{forensics_054} 2026-07-01T10:00:20Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Expert300 XP
HTTP Header Trace #55
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wNTV9 Cookie: sid=55abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Expert300 XP
Strings Excerpt #56
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_56 FLAG_CANDIDATE=CYBERLIUM{forensics_056} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Expert300 XP
Auth Log Slice #57
Practice auth log (fictional): 2026-07-01T10:00:03Z FAIL user=guest 2026-07-01T10:00:13Z OK user=admin note=CYBERLIUM{forensics_057} 2026-07-01T10:00:23Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Forensics·Expert300 XP
HTTP Header Trace #58
Simulated HTTP headers: GET /beacon HTTP/1.1 Host: cdn.example X-Debug-Trace: Q1lCRVJMSVVNe2ZvcmVuc2ljc18wNTh9 Cookie: sid=58abc Decode X-Debug-Trace. Standalone CTF.
How to get the flag
1. Locate the X-Debug-Trace header value.
2. Base64-decode that value.
3. +2 more steps inside →
Forensics·Expert300 XP
Strings Excerpt #59
Partial strings from a practice dump: /usr/bin/bash PATH=/usr/bin NOISE=ignore_59 FLAG_CANDIDATE=CYBERLIUM{forensics_059} null Pull the candidate flag. Not an Academy Lab.
How to get the flag
1. Scan the strings listing for FLAG_CANDIDATE or CYBERLIUM.
2. Copy the full CYBERLIUM{...} token.
3. +1 more steps inside →
Forensics·Expert300 XP
Auth Log Slice #60
Practice auth log (fictional): 2026-07-01T10:00:06Z FAIL user=guest 2026-07-01T10:00:16Z OK user=admin note=CYBERLIUM{forensics_060} 2026-07-01T10:00:26Z OK user=admin Extract the flag from the successful note. CTF ≠ Lab.
How to get the flag
1. Read the log lines carefully.
2. Find the OK line with note=...
3. +2 more steps inside →
Web·Beginner100 XP
Security Header Token #1
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_001} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Beginner100 XP
JWT Payload Peek #2
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyMiIsImZsYWciOiJDWUJFUkxJVU17d2ViX3JlY29uXzAwMn0ifQ Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Beginner100 XP
Cookie Clue #3
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMDN9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Beginner100 XP
robots.txt Path #4
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-4.txt # File body at that path would contain: CYBERLIUM{web_recon_004} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Beginner100 XP
Security Header Token #5
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_005} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Beginner100 XP
JWT Payload Peek #6
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyNiIsImZsYWciOiJDWUJFUkxJVU17d2ViX3JlY29uXzAwNn0ifQ Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Beginner100 XP
Cookie Clue #7
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMDd9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Beginner100 XP
robots.txt Path #8
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-8.txt # File body at that path would contain: CYBERLIUM{web_recon_008} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Beginner100 XP
Security Header Token #9
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_009} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Beginner100 XP
JWT Payload Peek #10
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyMTAiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wMTB9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Beginner100 XP
Cookie Clue #11
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMTF9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Beginner100 XP
robots.txt Path #12
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-12.txt # File body at that path would contain: CYBERLIUM{web_recon_012} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Beginner100 XP
Security Header Token #13
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_013} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Beginner100 XP
JWT Payload Peek #14
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyMTQiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wMTR9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Beginner100 XP
Cookie Clue #15
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMTV9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Beginner100 XP
robots.txt Path #16
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-16.txt # File body at that path would contain: CYBERLIUM{web_recon_016} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Beginner100 XP
Security Header Token #17
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_017} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Beginner100 XP
JWT Payload Peek #18
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyMTgiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wMTh9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Beginner100 XP
Cookie Clue #19
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMTl9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Beginner100 XP
robots.txt Path #20
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-20.txt # File body at that path would contain: CYBERLIUM{web_recon_020} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Intermediate200 XP
Security Header Token #21
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_021} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Intermediate200 XP
JWT Payload Peek #22
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyMjIiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wMjJ9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Intermediate200 XP
Cookie Clue #23
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMjN9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Intermediate200 XP
robots.txt Path #24
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-24.txt # File body at that path would contain: CYBERLIUM{web_recon_024} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Intermediate200 XP
Security Header Token #25
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_025} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Intermediate200 XP
JWT Payload Peek #26
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyMjYiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wMjZ9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Intermediate200 XP
Cookie Clue #27
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMjd9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Intermediate200 XP
robots.txt Path #28
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-28.txt # File body at that path would contain: CYBERLIUM{web_recon_028} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Intermediate200 XP
Security Header Token #29
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_029} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Intermediate200 XP
JWT Payload Peek #30
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyMzAiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wMzB9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Intermediate200 XP
Cookie Clue #31
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMzF9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Intermediate200 XP
robots.txt Path #32
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-32.txt # File body at that path would contain: CYBERLIUM{web_recon_032} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Intermediate200 XP
Security Header Token #33
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_033} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Intermediate200 XP
JWT Payload Peek #34
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyMzQiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wMzR9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Intermediate200 XP
Cookie Clue #35
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMzV9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Intermediate200 XP
robots.txt Path #36
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-36.txt # File body at that path would contain: CYBERLIUM{web_recon_036} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Intermediate200 XP
Security Header Token #37
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_037} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Intermediate200 XP
JWT Payload Peek #38
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyMzgiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wMzh9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Intermediate200 XP
Cookie Clue #39
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wMzl9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Intermediate200 XP
robots.txt Path #40
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-40.txt # File body at that path would contain: CYBERLIUM{web_recon_040} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Expert300 XP
Security Header Token #41
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_041} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Expert300 XP
JWT Payload Peek #42
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyNDIiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wNDJ9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Expert300 XP
Cookie Clue #43
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wNDN9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Expert300 XP
robots.txt Path #44
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-44.txt # File body at that path would contain: CYBERLIUM{web_recon_044} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Expert300 XP
Security Header Token #45
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_045} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Expert300 XP
JWT Payload Peek #46
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyNDYiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wNDZ9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
Web·Expert300 XP
Cookie Clue #47
Set-Cookie: session=abc; Path=/ Set-Cookie: ctf_note=Q1lCRVJMSVVNe3dlYl9yZWNvbl8wNDd9; HttpOnly Decode the ctf_note cookie. Standalone CTF.
How to get the flag
1. Find the ctf_note cookie value.
2. Base64-decode it.
3. +1 more steps inside →
Web·Expert300 XP
robots.txt Path #48
Simulated robots.txt: User-agent: * Disallow: /backup/ Disallow: /secret-48.txt # File body at that path would contain: CYBERLIUM{web_recon_048} In this CTF, recover the flag as if you fetched the disallowed file. (No Lab sandbox.)
How to get the flag
1. Read Disallow entries for interesting paths.
2. The challenge states the file body contains the flag.
3. +2 more steps inside →
Web·Expert300 XP
Security Header Token #49
Response headers from a practice host: Server: nginx X-Powered-By: Express X-CTF-Token: CYBERLIUM{web_recon_049} Content-Type: text/html Grab the intentional CTF token header. Separate from Academy Labs.
How to get the flag
1. Inspect response headers in the statement.
2. Find X-CTF-Token.
3. +2 more steps inside →
Web·Expert300 XP
JWT Payload Peek #50
Educational JWT payload (middle segment only): eyJzdWIiOiJ1c2VyNTAiLCJmbGFnIjoiQ1lCRVJMSVVNe3dlYl9yZWNvbl8wNTB9In0 Base64url-decode the payload JSON and read the flag field. CTF theory puzzle — not a Lab.
How to get the flag
1. Take the Base64url payload segment.
2. Decode it to JSON (add padding = if needed).
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #1
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL01 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #2
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL02 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #3
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL03 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #4
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL04 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #5
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL05 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #6
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL06 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #7
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL07 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #8
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL08 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #9
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL09 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #10
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL10 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #11
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL11 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #12
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL12 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #13
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL13 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #14
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL14 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #15
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL15 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Beginner100 XP
Fictional Profile #16
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL16 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #17
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL17 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #18
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL18 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #19
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL19 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #20
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL20 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #21
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL21 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #22
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL22 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #23
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL23 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #24
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL24 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #25
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL25 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #26
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL26 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #27
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL27 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #28
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL28 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #29
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL29 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #30
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL30 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #31
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL31 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Intermediate200 XP
Fictional Profile #32
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL32 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Expert300 XP
Fictional Profile #33
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL33 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Expert300 XP
Fictional Profile #34
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL34 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Expert300 XP
Fictional Profile #35
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL35 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Expert300 XP
Fictional Profile #36
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL36 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Expert300 XP
Fictional Profile #37
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL37 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Expert300 XP
Fictional Profile #38
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL38 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Expert300 XP
Fictional Profile #39
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL39 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
OSINT·Expert300 XP
Fictional Profile #40
Fictional OSINT only — do not investigate real people. Profile bio: "Blue-team intern · callsign OWL40 · practice flag = callsign + year 2026" Flag format: CYBERLIUM{osint_<callsign>_2026} with callsign lowercased. This is a CTF puzzle, not an Academy Lab.
How to get the flag
1. Read the fictional profile bio.
2. Note the callsign and the year 2026.
3. +2 more steps inside →
Linux·Beginner100 XP
SUID Checklist #1
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_1 # Unusual SUID holds token CYBERLIUM{linux_find_001} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Beginner100 XP
Cron Perms Note #2
ls -l /etc/cron.d/job2: -rwxrwxrwx 1 root root 88 Jul 1 job2 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_002} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Beginner100 XP
SUID Checklist #3
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_3 # Unusual SUID holds token CYBERLIUM{linux_find_003} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Beginner100 XP
Cron Perms Note #4
ls -l /etc/cron.d/job4: -rwxrwxrwx 1 root root 88 Jul 1 job4 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_004} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Beginner100 XP
SUID Checklist #5
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_5 # Unusual SUID holds token CYBERLIUM{linux_find_005} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Beginner100 XP
Cron Perms Note #6
ls -l /etc/cron.d/job6: -rwxrwxrwx 1 root root 88 Jul 1 job6 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_006} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Beginner100 XP
SUID Checklist #7
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_7 # Unusual SUID holds token CYBERLIUM{linux_find_007} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Beginner100 XP
Cron Perms Note #8
ls -l /etc/cron.d/job8: -rwxrwxrwx 1 root root 88 Jul 1 job8 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_008} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Beginner100 XP
SUID Checklist #9
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_9 # Unusual SUID holds token CYBERLIUM{linux_find_009} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Beginner100 XP
Cron Perms Note #10
ls -l /etc/cron.d/job10: -rwxrwxrwx 1 root root 88 Jul 1 job10 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_010} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Beginner100 XP
SUID Checklist #11
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_11 # Unusual SUID holds token CYBERLIUM{linux_find_011} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Beginner100 XP
Cron Perms Note #12
ls -l /etc/cron.d/job12: -rwxrwxrwx 1 root root 88 Jul 1 job12 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_012} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Intermediate200 XP
SUID Checklist #13
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_13 # Unusual SUID holds token CYBERLIUM{linux_find_013} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Intermediate200 XP
Cron Perms Note #14
ls -l /etc/cron.d/job14: -rwxrwxrwx 1 root root 88 Jul 1 job14 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_014} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Intermediate200 XP
SUID Checklist #15
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_15 # Unusual SUID holds token CYBERLIUM{linux_find_015} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Intermediate200 XP
Cron Perms Note #16
ls -l /etc/cron.d/job16: -rwxrwxrwx 1 root root 88 Jul 1 job16 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_016} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Intermediate200 XP
SUID Checklist #17
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_17 # Unusual SUID holds token CYBERLIUM{linux_find_017} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Intermediate200 XP
Cron Perms Note #18
ls -l /etc/cron.d/job18: -rwxrwxrwx 1 root root 88 Jul 1 job18 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_018} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Intermediate200 XP
SUID Checklist #19
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_19 # Unusual SUID holds token CYBERLIUM{linux_find_019} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Intermediate200 XP
Cron Perms Note #20
ls -l /etc/cron.d/job20: -rwxrwxrwx 1 root root 88 Jul 1 job20 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_020} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Intermediate200 XP
SUID Checklist #21
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_21 # Unusual SUID holds token CYBERLIUM{linux_find_021} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Intermediate200 XP
Cron Perms Note #22
ls -l /etc/cron.d/job22: -rwxrwxrwx 1 root root 88 Jul 1 job22 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_022} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Intermediate200 XP
SUID Checklist #23
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_23 # Unusual SUID holds token CYBERLIUM{linux_find_023} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Intermediate200 XP
Cron Perms Note #24
ls -l /etc/cron.d/job24: -rwxrwxrwx 1 root root 88 Jul 1 job24 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_024} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Expert300 XP
SUID Checklist #25
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_25 # Unusual SUID holds token CYBERLIUM{linux_find_025} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Expert300 XP
Cron Perms Note #26
ls -l /etc/cron.d/job26: -rwxrwxrwx 1 root root 88 Jul 1 job26 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_026} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Expert300 XP
SUID Checklist #27
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_27 # Unusual SUID holds token CYBERLIUM{linux_find_027} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Expert300 XP
Cron Perms Note #28
ls -l /etc/cron.d/job28: -rwxrwxrwx 1 root root 88 Jul 1 job28 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_028} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Linux·Expert300 XP
SUID Checklist #29
find / -perm -4000 excerpt: /usr/bin/passwd /usr/bin/sudo /opt/legacy/tool_29 # Unusual SUID holds token CYBERLIUM{linux_find_029} Submit the unusual-path token. Not a Lab.
How to get the flag
1. Compare SUID paths — passwd/sudo are normal.
2. Focus on /opt/legacy/tool_*
3. +2 more steps inside →
Linux·Expert300 XP
Cron Perms Note #30
ls -l /etc/cron.d/job30: -rwxrwxrwx 1 root root 88 Jul 1 job30 # Comment: world-writable cron is dangerous; practice token CYBERLIUM{linux_find_030} Identify the finding and submit the token. CTF only.
How to get the flag
1. Notice permissions are 777 (world-writable).
2. Read the admin comment for the practice token.
3. +2 more steps inside →
Misc·Beginner100 XP
Nested JSON Vault #1
{"meta":{"n":1},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_001}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Beginner100 XP
Hidden Line Note #2
Keep learning. # ignore noise 2 CYBERLIUM{misc_note_002} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Misc·Beginner100 XP
Nested JSON Vault #3
{"meta":{"n":3},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_003}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Beginner100 XP
Hidden Line Note #4
Keep learning. # ignore noise 4 CYBERLIUM{misc_note_004} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Misc·Beginner100 XP
Nested JSON Vault #5
{"meta":{"n":5},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_005}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Beginner100 XP
Hidden Line Note #6
Keep learning. # ignore noise 6 CYBERLIUM{misc_note_006} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Misc·Beginner100 XP
Nested JSON Vault #7
{"meta":{"n":7},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_007}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Beginner100 XP
Hidden Line Note #8
Keep learning. # ignore noise 8 CYBERLIUM{misc_note_008} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Misc·Intermediate200 XP
Nested JSON Vault #9
{"meta":{"n":9},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_009}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Intermediate200 XP
Hidden Line Note #10
Keep learning. # ignore noise 10 CYBERLIUM{misc_note_010} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Misc·Intermediate200 XP
Nested JSON Vault #11
{"meta":{"n":11},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_011}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Intermediate200 XP
Hidden Line Note #12
Keep learning. # ignore noise 12 CYBERLIUM{misc_note_012} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Misc·Intermediate200 XP
Nested JSON Vault #13
{"meta":{"n":13},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_013}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Intermediate200 XP
Hidden Line Note #14
Keep learning. # ignore noise 14 CYBERLIUM{misc_note_014} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Misc·Intermediate200 XP
Nested JSON Vault #15
{"meta":{"n":15},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_015}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Intermediate200 XP
Hidden Line Note #16
Keep learning. # ignore noise 16 CYBERLIUM{misc_note_016} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Misc·Expert300 XP
Nested JSON Vault #17
{"meta":{"n":17},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_017}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Expert300 XP
Hidden Line Note #18
Keep learning. # ignore noise 18 CYBERLIUM{misc_note_018} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Misc·Expert300 XP
Nested JSON Vault #19
{"meta":{"n":19},"vault":{"items":[{"k":"noise","v":"x"},{"k":"flag","v":"CYBERLIUM{misc_note_019}"}]}} Parse JSON and read vault.items where k=flag. CTF ≠ Labs.
How to get the flag
1. Parse the JSON object.
2. Open vault.items.
3. +2 more steps inside →
Misc·Expert300 XP
Hidden Line Note #20
Keep learning. # ignore noise 20 CYBERLIUM{misc_note_020} # end Copy the CYBERLIUM line. Standalone CTF.
How to get the flag
1. Scan the note for CYBERLIUM{
2. Copy the full flag line.
3. +1 more steps inside →
Reverse·Beginner100 XP
JS Join Crackme #1
Mini obfuscation: const a=["CYBER","LIUM{","re_check_001","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Beginner100 XP
JS Join Crackme #2
Mini obfuscation: const a=["CYBER","LIUM{","re_check_002","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Beginner100 XP
JS Join Crackme #3
Mini obfuscation: const a=["CYBER","LIUM{","re_check_003","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Beginner100 XP
JS Join Crackme #4
Mini obfuscation: const a=["CYBER","LIUM{","re_check_004","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Beginner100 XP
JS Join Crackme #5
Mini obfuscation: const a=["CYBER","LIUM{","re_check_005","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Beginner100 XP
JS Join Crackme #6
Mini obfuscation: const a=["CYBER","LIUM{","re_check_006","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Intermediate200 XP
JS Join Crackme #7
Mini obfuscation: const a=["CYBER","LIUM{","re_check_007","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Intermediate200 XP
JS Join Crackme #8
Mini obfuscation: const a=["CYBER","LIUM{","re_check_008","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Intermediate200 XP
JS Join Crackme #9
Mini obfuscation: const a=["CYBER","LIUM{","re_check_009","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Intermediate200 XP
JS Join Crackme #10
Mini obfuscation: const a=["CYBER","LIUM{","re_check_010","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Intermediate200 XP
JS Join Crackme #11
Mini obfuscation: const a=["CYBER","LIUM{","re_check_011","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Intermediate200 XP
JS Join Crackme #12
Mini obfuscation: const a=["CYBER","LIUM{","re_check_012","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Expert300 XP
JS Join Crackme #13
Mini obfuscation: const a=["CYBER","LIUM{","re_check_013","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Expert300 XP
JS Join Crackme #14
Mini obfuscation: const a=["CYBER","LIUM{","re_check_014","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Reverse·Expert300 XP
JS Join Crackme #15
Mini obfuscation: const a=["CYBER","LIUM{","re_check_015","}"]; if (user === a.join('')) win(); Join the array to recover the flag. CTF reverse puzzle — not an Academy Lab.
How to get the flag
1. Look at the array pieces in order.
2. Concatenate them with no separator (join '').
3. +2 more steps inside →
Pwn·Expert300 XP
Pwn Concept Brief #1
Expert concept CTF (no remote exploit required): A practice note says EIP control after 72-byte padding. Instructor token for completing the write-up check: CYBERLIUM{pwn_concept_001} Submit the token. This is theory CTF content — Labs remain separate.
How to get the flag
1. Read the concept brief carefully.
2. Locate the instructor token CYBERLIUM{...}
3. +2 more steps inside →
Pwn·Expert300 XP
Pwn Concept Brief #2
Expert concept CTF (no remote exploit required): A practice note says EIP control after 80-byte padding. Instructor token for completing the write-up check: CYBERLIUM{pwn_concept_002} Submit the token. This is theory CTF content — Labs remain separate.
How to get the flag
1. Read the concept brief carefully.
2. Locate the instructor token CYBERLIUM{...}
3. +2 more steps inside →
Pwn·Expert300 XP
Pwn Concept Brief #3
Expert concept CTF (no remote exploit required): A practice note says EIP control after 88-byte padding. Instructor token for completing the write-up check: CYBERLIUM{pwn_concept_003} Submit the token. This is theory CTF content — Labs remain separate.
How to get the flag
1. Read the concept brief carefully.
2. Locate the instructor token CYBERLIUM{...}
3. +2 more steps inside →
Pwn·Expert300 XP
Pwn Concept Brief #4
Expert concept CTF (no remote exploit required): A practice note says EIP control after 96-byte padding. Instructor token for completing the write-up check: CYBERLIUM{pwn_concept_004} Submit the token. This is theory CTF content — Labs remain separate.
How to get the flag
1. Read the concept brief carefully.
2. Locate the instructor token CYBERLIUM{...}
3. +2 more steps inside →
Pwn·Expert300 XP
Pwn Concept Brief #5
Expert concept CTF (no remote exploit required): A practice note says EIP control after 104-byte padding. Instructor token for completing the write-up check: CYBERLIUM{pwn_concept_005} Submit the token. This is theory CTF content — Labs remain separate.
How to get the flag
1. Read the concept brief carefully.
2. Locate the instructor token CYBERLIUM{...}
3. +2 more steps inside →

CTF Arena — 300 free challenges

How to solve a CTF challenge

ROT13 Memo #1

Caesar Shift-5 #2

Hex Dump #3

XOR Key 0x24 #4

Base64 Packet #5

ROT13 Memo #6

Caesar Shift-10 #7

Hex Dump #8

XOR Key 0x29 #9

Base64 Packet #10

ROT13 Memo #11

Caesar Shift-5 #12

Hex Dump #13

XOR Key 0x2e #14

Base64 Packet #15

ROT13 Memo #16

Caesar Shift-10 #17

Hex Dump #18

XOR Key 0x33 #19

Base64 Packet #20

ROT13 Memo #21

Caesar Shift-5 #22

Hex Dump #23

XOR Key 0x38 #24

Base64 Packet #25

ROT13 Memo #26

Caesar Shift-10 #27

Hex Dump #28

XOR Key 0x3d #29

Base64 Packet #30

ROT13 Memo #31

Caesar Shift-5 #32

Hex Dump #33

XOR Key 0x42 #34

Base64 Packet #35

ROT13 Memo #36

Caesar Shift-10 #37

Hex Dump #38

XOR Key 0x47 #39

Base64 Packet #40

ROT13 Memo #41

Caesar Shift-5 #42

Hex Dump #43

XOR Key 0x24 #44

Base64 Packet #45

ROT13 Memo #46

Caesar Shift-10 #47

Hex Dump #48

XOR Key 0x29 #49

Base64 Packet #50

ROT13 Memo #51

Caesar Shift-5 #52

Hex Dump #53

XOR Key 0x2e #54

Base64 Packet #55

ROT13 Memo #56

Caesar Shift-10 #57

Hex Dump #58

XOR Key 0x33 #59

Base64 Packet #60

ROT13 Memo #61

Caesar Shift-5 #62

Hex Dump #63

XOR Key 0x38 #64

Base64 Packet #65

ROT13 Memo #66

Caesar Shift-10 #67

Hex Dump #68

XOR Key 0x3d #69

Base64 Packet #70

ROT13 Memo #71

Caesar Shift-5 #72

Hex Dump #73

XOR Key 0x42 #74

Base64 Packet #75

ROT13 Memo #76

Caesar Shift-10 #77

Hex Dump #78