Oct
25

Hack.lu 2013 CTF – Crypto 350 (BREW’r’Y)

BREW’r’Y (Category: Crypto) Author(s): dwuid Finally, the robots managed to sneak into one of our breweries. I guess I won’t have to explain how bad that really is. That darn non-physical ones even shutdown our login system. Shiny thing, advanced technology, all based on fingerprints. Been secure as hell. If only it was running. Well,… Continue reading »

Sep
25

hack.lu CTF 2011 FluxScience (450)

Category: reversing Thanks to a former employee of FluxScience (one of our competitors), we managed to get hands on some important files which might help us revealing company secrets. Attached you will find the files. The employee who provided them got fired. You might be lucky and find his account still working: FLUX-38B273DD75860083-0B3DD6B02EC5B9B1-4AFFBAC2EB8B4D17 He might… Continue reading »

Sep
22

hack.lu CTF 2011 Wipe out the Klingons (400)

Category: crypto We already made it. The evil Klingons agression is nearly fended. But their final mothership is well protected and even sacrifing a huge number of battleships caused only minor damage. Spies told us an unclear message caused most technical operators and the commander to leave the ship. Unfortunately we are unable to locate… Continue reading »

Sep
21

hack.lu CTF 2011 Simplexor (200)

Category: crypto To get a better security we deceided to encrypt our most secret document with the secure xor-algorithm. Unfortunately we lost the key. Now we are sad. Can you help us recovering the key? Download Summary: recovering multibyte xor-key, using autocorrelation

Sep
21

hack.lu CTF 2011 Antique Space Shuttle (300)

Category: exploiting Your command is to get as much information about the crew of an antique space shuttle. We know our acient father used finger as reference point at nc ctf.hack.lu 2003 Summary: bash injection, and buffer overflow on a suid binary to get more privilegies

Sep
21

hack.lu CTF 2011 Space Station 0xB321054A (300)

Category: exploiting You have seen a deserted space station. Your task is to enter it. The first barrier is the access system. But you can find a module with the application on it. Here is the file: download What is the key? (There is also station A, but station B is the advanced one.) Summary:… Continue reading »

Nov
02

Hack.lu 2010 CTF #22 (Pirates Wisdom) writeup

Pirates Wisdom Captian Iglo heard there is a secret wisdom in the well known pirate wisdom system. Log in to ssh pirates.fluxfingers.net:9022 user: ctf password: ctf and get the content of key.txt. You get rewarded with 300 coins. binary Summary: simple heap’s chunk reusage error with a bit obfuscated logic

Oct
31

Hack.lu 2010 CTF #1 (Fun 300, Rock Lizard Spock) writeup

On the high seas, the nights get boring. Try to win the game against the captain! pirates.fluxfingers.net port 6565/tcp Let’s go & connect there: > nc pirates.fluxfingers.net 6565 /9j/4AAQSkZJRgABAQEAYABgAAD//gAJbWQ1d2luc//bAEMABQ MEBAQDBQQEBAUFBQYHDAgHBwcHDwsLCQwRDxISEQ8RERMWHBcT <…> EgWAYlOhQqadCpxQPCn4JDjQoVacgqCQ4dtCAY4+FChVJb7BVE A6fCnKIB0+FChSuX3C8XQPuhoUKFd+JM//Z The service gives us some base64 and waits 2 seconds for reply. Unbase64ing the data, we get this jpeg: There is no… Continue reading »

Oct
31

Hack.lu 2010 CTF #13 (My Cool Blog) writeup

Captain Rumbarrel is shocked because he found out that the filthy pirate Boozybold has stolen a whole shipment of rum! So Rumbarrel wants his revenge by hacking Boozybolds cool blog. Unfortunately he can not hack, so help him and get 250 gold coins! From main page of his cool blog, we get three main points:… Continue reading »

Oct
31

Hack.lu 2010 CTF #3, #11, #14 (Most Epic Challenges :) writeup

Task #3 – Like skies that are so blue Sometime even pirates have a lazy sunday… download 0.  1. Open in your favorite image editor (ms paint) 2. Do a fill: 3. Md5 of the original file is the answer: 032c49411912397eea2a7d906dab5f7e Task #11 – Ecrime Business Cap’n Bill Greasepalms wants to start an ecrime business.… Continue reading »

Oct
31

Hack.lu 2010 CTF #17 (Brainfuck) writeup

You found a backdoor on Captain Brainfuck’s webspace. Exploit it and read his secret file! The page only says ‘happy hacking’, so what would we be doing without its source… [source mirror] “Source” in fact is a zip archive with php code appended: PK <..zip binary trash..> <?php @ob_clean();$z=zip_open(__FILE__); eval($f=zip_entry_read(zip_read($z),1000));@ob_end_flush();?> It simply reads itself (the… Continue reading »

Oct
31

Hack.lu 2010 CTF #16 (Rattlesnake’s Riddle) writeup

Solve this riddle to impress Captain Rattlesnake! download The .pyc file is a byte-compiled python code, and there is a wonderful tool called uncompyle to deal with it. $ decompyle secret.pyc > secret.py The decompyled file: 1. Takes 3 arguments 2. Checks 2nd to be 1337 3. Calculates ‘token‘ value, which is 11111112671 4. After some… Continue reading »

Oct
30

Hack.lu 2010 CTF Challenge #8 Writeup

Sad Little Pirate (150) Our sad little pirate haes lost his password. It is known that the pirate has just one hand left; his left hand. So the paessword input is quite limited. Also he can still remember that the plaintext started with “674e2” and his password with “wcwteseawx” Please help the sad pirate finding… Continue reading »

Oct
30

Hack.lu 2010 CTF Challenge #7 Writeup

Breiers Deathmatch (150) Schnuce Breier has challenged you to a cryptographer’s deathmatch. Connect to pirates.fluxfingers.net 8007/tcp and get the secret number. $ nc pirates.fluxfingers.net 8007 Hi. This is your friendly ‘Decryption Oracle’ We have implemented a well-known public-key cryptosystem. Guess which ;) Modulo: 5628290459057877291809182450381238927697314822133923421169378 062922140081498734424133112032854812341 Generator: 99 Public Key: 135744434201778324839308712462911647727754874814096844915 5264250239122362719894347099351280643528244 Ciphertext: (44750535504622985677351849167148532593337860047243938284 03819968944371696234280482660523326406427034, 40867215175893797288404… Continue reading »

Oct
30

Hack.lu 2010 CTF Challenge #10 Writeup

#10 – Chip Forensic To solve this task we have something like this (original image is lost) and hex string: 0B 12 0F 0F 1C 4A 4C 0D 4D 15 12 0A 08 15. What we see on image? Some USB device. Those who have seen them on ebay or on other sites knows that… Continue reading »

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