Technical Support

Comes with hint that flag may be in discord channel - #ctf-open-ticket

With the hint, head over to the discord channel #ctf-open-ticket and grab the same flag as last year flag:

flag{a98373a74abb8c5ebb8f5192e034a91c}

Read The Rules

Follow link provided. View the page source code and perform a search for flag{ to find the same flag as last year:

flag{90bc54705794a62015369fd8e86e557b}

Too many bits

Decode binary string with CyberChef:

flag{d01471702a10134cdad1ddde06678f2f}

MatryoshkaQR

Render and parse the QR code using CyberChef which produces PNG bytes. Tried cleaning up in CyberChef, then gave up and just used Python to write the bytes to a file. Copy the new file into CyberChef again to get the flag:

flag{01c6e24c48f48856ee3adcca00f86e9b}

No need for Brutus

Google “brutus cryptography” and get results referencing Caesar/Vigenere - missed the plaintext when looking at Caesar in CyberChef, so ended up using dcode to decode with key (QQQ) and get the plaintext: caesarissimplenoneedforbrutus which means flag in requested format is:

flag{c945bb2173e7da5a292527bbbc825d3f}

Cattle

Given the name, and content of the file I Googled for “cow cipher” and found this link - entered the content and decrypted for the flag:

flag{6cd6392eb609c6ae4c332ef6a321d9dd}

Unbelievable

Check file format - it isn’t an mp3, but a PNG - change extension and open to get the flag:

flag{a85466991f0a8dc3d9837a5c32fa0c91}

TXT Message

Click the link to see reference to Octal - use this site to get the TXT record, copy into CyberChef and decode with Octal to get the flag:

flag{14e072f705d45882401d141c562fdc0b}

Whamazon

Given this is a warmup challenge, assume some form of ‘bogus’ entry will enable me to beat the system. Submit a negative integer to get enough money i.e. -111111111111111111111. Then buy the flag, win Rock, Paper, Scissors (simple logic…)

flag{18bdd83cee5690321bb14c70465d3408}

Mystery

Use an online Enigma emulator https://cryptii.com/pipes/enigma-machine to crack the code with the given settings:

flag{fdfeabcacbebfbadaefbeccaadddbafe}

I Can’t SSH

Since we have the private key to use, try connecting with -i to pass the key file - get message about permissions being too open so fix with chmod 600 id_rsa. Get a new errors about the key being invalid. cat to terminal and spot a missing newline at the end, add this and connect successfully. List directory then cat the flag file:

flag{ee1f28722ec1ce1542aa1b486dbb1361}