Overthewire Leviathan Level 4

Solution for the Overthewire.org Leviathan level 4

Level Goal

There is no information for this level, intentionally.

Walkthrough

Login to the server using the password obtained from the previous level Leviathan level 3.

username: leviathan4

ssh leviathan4@leviathan.labs.overthewire.org -p 2223

With no description given first thing we do is check what is in the home directory.

leviathan4@leviathan:~$ ls -al
total 24
drwxr-xr-x  3 root root       4096 Aug 26  2019 .
drwxr-xr-x 10 root root       4096 Aug 26  2019 ..
-rw-r--r--  1 root root        220 May 15  2017 .bash_logout
-rw-r--r--  1 root root       3526 May 15  2017 .bashrc
-rw-r--r--  1 root root        675 May 15  2017 .profile
dr-xr-x---  2 root leviathan4 4096 Aug 26  2019 .trash

There is a directory named .trash. Change directory into .trash and check what it contains.

leviathan4@leviathan:~$ cd .trash/
leviathan4@leviathan:~/.trash$ ls -al
dr-xr-x--- 2 root       leviathan4 4096 Aug 26  2019 .
drwxr-xr-x 3 root       root       4096 Aug 26  2019 ..
-r-sr-x--- 1 leviathan5 leviathan4 7352 Aug 26  2019 bin

There is an executable called bin and running it prints out 1’s and 0’s.

leviathan4@leviathan:~/.trash$ ./bin
01010100 01101001 01110100 01101000 00110100 01100011 01101111 01101011 01100101 01101001 00001010

The 1’s and 0’s are binary representation of ascii.
We need to convert the binary back to ascii.

To do this we use Python3 and binascii library.

leviathan4@leviathan:~/.trash$ python3
Python 3.5.3 (default, Sep 27 2018, 17:25:39) 
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import binascii
>>> n = int('0b0101010001101001011101000110100000110100011000110110111101101011011001010110100100001010' , 2)
>>> s = binascii.unhexlify('%x' % n).decode()
>>> print(s)
Tit*******