Bad man

200 punktów

Author: n00bmaster

We have recently received reports about a hacker who goes by the alias und3rm4t3r. He has been threatening innocent people for money and must be stopped. Help us find him and get us the flag.

Solution

Odnalazłem profil użytkownika und3rm4t3r na Twitterze (https://twitter.com/und3rm4t3r/). Jeden z tweetów wydał mi się bardzo interesujący:

Postanowiłem sprawdzić stronę w Wayback Machine (https://web.archive.org/web/20200723112257/twitter.com/und3rm4t3r/) i znalazłem flagę :-)

DUCTF{w4y_b4ck_1n_t1m3_w3_g0}

Pretty Good Pitfall

200 punktów

Author: k0wa1ski#6150

PGP/GPG/GnuPG/OpenPGP is great! I reckon you can't find the message, because it looks scrambled!

Attached files: flag.txt.gpg (sha256: dad03ac28b7294c8696eeac21d11159c3dcfc8ed226438804fe82b4fb9f6ad87)

Solution

gpg --output doc flag.txt.gpg

DUCTF{S1GN1NG_A1NT_3NCRYPT10N}

Addition

200 punktów

Author: n00bmaster

Joe is aiming to become the next supreme coder by trying to make his code smaller and smaller. His most recent project is a simple calculator which he reckons is super secure because of the "filters" he has in place. However, he thinks that he knows more than everyone around him. Put Joe in his place and grab the flag.

https://chal.duc.tf:30302/

Solution

Ok, a więc zadanie zaczynamy od webaplikacji z kalkulatorem. Wartościową wskazówką jest informacja, iż strona napisana jest w Pythonie.

Flagę zdobyłem korzystając z następującego payloadu: '{}'.format(open('main.py','r').read())

DUCTF{3v4L_1s_D4ng3r0u5}