picoCTF 2022: Crypto – Morse Code

Ulli Weichert/ April 3, 2022/ IT-Security, Write-Ups/ 0Kommentare

morse-code Description Morse code is well known. Can you decrypt this? Download the file here. Wrap your answer with picoCTF{}, put underscores in place of pauses, and use all lowercase. Solving The soundfile is a morse code You could either translate it by your self with the morse alphabet or use this link Change all characters to lowercase and replace

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picoCTF 2022: Crypto – credstuff

Ulli Weichert/ April 3, 2022/ IT-Security, Write-Ups/ 0Kommentare

credstuff Description We found a leak of a blackmarket website’s login credentials. Can you find the password of the user cultiris and successfully decrypt it? Download the leak here. The first user in usernames.txt corresponds to the first password in passwords.txt. The second user corresponds to the second password, and so on. Solving We got a tar file – extract

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picoCTF 2022: Crypto – basic_mod2

Ulli Weichert/ April 2, 2022/ IT-Security, Write-Ups/ 0Kommentare

basic-mod2 Description A new modular challenge! Download the message here. Take each number mod 41 and find the modular inverse for the result. Then map to the following character set: 1-26 are the alphabet, 27-36 are the decimal digits, and 37 is an underscore. Wrap your decrypted message in the picoCTF flag format (i.e. picoCTF{decrypted_message}) Solving This challenge is similar

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picoCTF 2022: Crypto – basic_mod1

Ulli Weichert/ März 30, 2022/ IT-Security, Write-Ups/ 0Kommentare

basic-mod1 Description We found this weird message being passed around on the servers, we think we have a working decrpytion scheme. Download the message here. Take each number mod 37 and map it to the following character set: 0-25 is the alphabet (uppercase), 26-35 are the decimal digits, and 36 is an underscore. Wrap your decrypted message in the picoCTF

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TheFewChosen CTF 2021: Forensics – Ocean / Writeup

Ulli Weichert/ November 28, 2021/ IT-Security, Write-Ups/ 0Kommentare

OCEAN What can you do in an ocean of files? nc server.challenge.ctf.thefewchosen.com 1338 Hints There is an official hint: Hint for ocean: The chal file is not relevant. That’s just a shell (basically the entrypoint). Try listing folders and subfolders Todos So we looked around for a while and found this directory (Magic trick was to use ls -R instead

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TheFewChosen CTF 2021: MISC – Lost my Head / Writeup

Ulli Weichert/ November 28, 2021/ IT-Security, Write-Ups/ 0Kommentare

Lost my Head Oh no! Help! I’ve lost my head! Can you tell me the street name of the trash bin I lost it in? Maybe I can still find it… Flag format: TFCCTF{street_name_and_street_number_as_seen_on_google_maps_separated_by_underscores} Challenge authors: hofill, tomadimitrie Solving Like always we should first check strings, file and so on. Please see the logfiles. In the exif we can find

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MetaRed CTF 2021: Stego – Noise / Writeup

Ulli Weichert/ November 18, 2021/ IT-Security, Write-Ups/ 0Kommentare

Noise Messi: ‚When the year starts, the objective is to win with all the team, personal records are secondary‘ Todos Given was this picture: In this stego challenges the first approach is to check the file type and look for some strings. $ ~ # file challenge.png challenge.png: PNG image data, 926 x 1262, 8-bit grayscale, non-interlaced That looks normal…

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MetaRed CTF 2021: Stego – Friends / Writeup

Ulli Weichert/ November 18, 2021/ IT-Security, Write-Ups/ 0Kommentare

Friends Bielsa: ‚Everything is allowed, except stop fighting‘ Given was this image: Todos Like always – I check strings and exiftools and the file itself! But no command give us something. $ ~ # file messi.jpg messi.jpg: JPEG image data, JFIF standard 1.01, aspect ratio, density 1×1, segment length 16, baseline, precision 8, 720×628, components 3 exiftool messi.jpg > messi.jpg_exifdata

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