Misc - whatisthis - writeup

Description

Intelligence has found same weird material from Mr. Codeshankar (yes,him again). So it is your task now to find out whats contained in it. The link is here

Writeup

after unpacking the zip file whatisthis.zip I get an featuredImage file whatisthis.png

The file itself is broken and cannot be opened.

After checking with the file command what that file actually is I am presented with the following: whatisthis.png: POSIX tar archive

So its a tar file

So lets rename this file to a proper file extension

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cp whatisthis.png whatisthis.tar

Now I will try to extract that archive

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tar -xf whatisthis.tar

I get a lot of random folders

each contains three files:

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2
3

json,
layer.tar,
VERSION

VERSION is always 1.0

So lets look at the content of all those weird json files

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cat *.json

what immediately sparks my eyes is the following:

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cat /etc/m/m/nothing.txt

looks like we are dealing with docker containers here …

There are still a lot of tar files inside each subfolders

so lets extract them

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find . -name '*.tar' -execdir tar -xzvf '{}' \;

After digging a lot around I found the file etc/m/m/nothing.txt

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cat etc/m/m/nothing.txt

CTF{D0cker_ent3r5_the_p4rty}

So the flag is

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CTF{D0cker_ent3r5_the_p4rty}