Level goal: The password for the next level is stored in /etc/bandit_pass/bandit14 and can only be read by user bandit14. For this level, you don’t get the next password, but you get a private SSH key that can be used to log into the next level. Note: localhost is a hostname that refers to the machine you are working on

 

This level tests us on an essential skills on navigating around various servers using SSH protocol – to login without a password. Many organisations use this method of accessing their servers as they will not be prone to brute force password attack.

To access the next level, simple login using the sshkey.private which was provided to you on the root directory using the following command:

bandit13@melinda:~$ ssh -i ./sshkey.private bandit14@localhost

Next, if you really want to know the password, you can read it from the /etc/bandit_pass/bandit14 path. As mentioned in the level 0 introduction page, all level’s passwords are stored in that path but they can only be accessed by the level’s user themselves.

The password to gain access to the next level is 4wcYUJFw0k0XLShlDzztnTBHiqxU3b3e.

Level goal: The password for the next level is stored in the file data.txt, which is a hexdump of a file that has been repeatedly compressed. For this level it may be useful to create a directory under /tmp in which you can work using mkdir. For example: mkdir /tmp/myname123. Then copy the datafile using cp, and rename it using mv (read the manpages!)

 

This level is one of the most tedious stage in this CTF challenge. First, let’s move the file to a new directory in the /tmp folder under your name (create one using the mkdir command!).

Now we have to perform a reverse hashdump using xxd command,

bandit12@melinda:/tmp/kongwenbin12$ xxd -r data.txt > kwbfile

After performing the reverse hashdump command and writing the output to a file (in my case, I have named it “kwbfile”), run the file command to check what kind of file is it.

bandit12@melinda:/tmp/kongwenbin12$ file kwbfile
kwbfile: gzip compressed data, was "data2.bin", from Unix, last modified: Fri Nov 14 10:32:20 2014, max compression

From here onwards, the flow goes like this,

1. Identify what type of file is this, using the file command
2. Rename it to that particular file format, using the mv command to change its file type
3. Decompress/unzip the files using the correct type of tool
4. Repeat the above process until you have the file

The following is a dump of the commands I have, it will be quite lengthy. However, it basically follows the flow which I described above. I have added a “line break” after each change in file type, to make it easier to follow. I hope it helps!

Scroll to the bottom for the password to gain access to the next level. 

bandit12@melinda:/tmp/kongwenbin12$ file kwbfile
kwbfile: gzip compressed data, was "data2.bin", from Unix, last modified: Fri Nov 14 10:32:20 2014, max compression
bandit12@melinda:/tmp/kongwenbin12$ mv kwbfile kwbfile.gz
bandit12@melinda:/tmp/kongwenbin12$ gzip -d kwbfile.gz

bandit12@melinda:/tmp/kongwenbin12$ file kwbfile
kwbfile: bzip2 compressed data, block size = 900k
bandit12@melinda:/tmp/kongwenbin12$ mv kwbfile kwbfile.bz2
bandit12@melinda:/tmp/kongwenbin12$ bzip2 -d kwbfile.bz2

bandit12@melinda:/tmp/kongwenbin12$ file kwbfile
kwbfile: gzip compressed data, was "data4.bin", from Unix, last modified: Fri Nov 14 10:32:20 2014, max compression
bandit12@melinda:/tmp/kongwenbin12$ mv kwbfile kwbfile.gz
bandit12@melinda:/tmp/kongwenbin12$ gzip -d kwbfile.gz

bandit12@melinda:/tmp/kongwenbin12$ file kwbfile
kwbfile: POSIX tar archive (GNU)
bandit12@melinda:/tmp/kongwenbin12$ mv kwbfile kwbfile.tar
bandit12@melinda:/tmp/kongwenbin12$ tar xvf kwbfile.tar
data5.bin

bandit12@melinda:/tmp/kongwenbin12$ file data5.bin
data5.bin: POSIX tar archive (GNU)
bandit12@melinda:/tmp/kongwenbin12$ mv data5.bin data5.tar
bandit12@melinda:/tmp/kongwenbin12$ tar xvf data5.tar
data6.bin

bandit12@melinda:/tmp/kongwenbin12$ file data6.bin
data6.bin: bzip2 compressed data, block size = 900k
bandit12@melinda:/tmp/kongwenbin12$ mv data6.bin data6.bz2
bandit12@melinda:/tmp/kongwenbin12$ bzip2 -d data6.bz2

bandit12@melinda:/tmp/kongwenbin12$ file data6
data6: POSIX tar archive (GNU)
bandit12@melinda:/tmp/kongwenbin12$ mv data6 data6.tar
bandit12@melinda:/tmp/kongwenbin12$ tar xvf data6.tar
data8.bin

bandit12@melinda:/tmp/kongwenbin12$ file data8.bin
data8.bin: gzip compressed data, was "data9.bin", from Unix, last modified: Fri Nov 14 10:32:20 2014, max compression
bandit12@melinda:/tmp/kongwenbin12$ mv data8.bin data8.gz
bandit12@melinda:/tmp/kongwenbin12$ gzip -d data8.gz

bandit12@melinda:/tmp/kongwenbin12$ file data8
data8: ASCII text
bandit12@melinda:/tmp/kongwenbin12$ cat data8
The password is 8ZjyCRiBWFYkneahHwxCv3wb2a1ORpYL

The password to gain access to the next level is 8ZjyCRiBWFYkneahHwxCv3wb2a1ORpYL.

Level goal: The password for the next level is stored in the file data.txt, where all lowercase (a-z) and uppercase (A-Z) letters have been rotated by 13 positions

As provided in the hint, we are required to perform a ROT13 “decode” on the file given. If you have been following this blog, you would have seen this InfoSec CTF which also requires to perform ROT13 decode to find the flag.

First, let’s look at the clue,

bandit11@melinda:~$ cat data.txt
Gur cnffjbeq vf 5Gr8L4qetPEsPk8htqjhRK8XSP6x2RHh

Now, we can decode this using the ROT13 tool.

The password to gain access to the next level is 5Te8Y4drgCRfCx8ugdwuEX8KFC6k2EUu.

Level goal: The password for the next level is stored in the file data.txt, which contains base64 encoded data

This level basically introduce us to base64 encoding, one of the most commonly used method to encode data in the wild, however, it is easily recognized and decoded due to all the tools available online. I have covered a few write up other CTF games that uses base64 encoding as well, such as the InfoSec CTF.

Since the server itself is running on a Linux distribution and all Unix operating systems has inbuilt support for the base64 command, we are easily perform a base64 decode directly.

bandit10@melinda:~$ base64 -d data.txt
The password is IFukwKGsFW8MOq3IRFqrxE1hxTNEbUPR

The password to gain access to the next level is IFukwKGsFW8MOq3IRFqrxE1hxTNEbUPR.

Level goal: The password for the next level is stored in the file data.txt in one of the few human-readable strings, beginning with several ‘=’ characters.

This level is similar to previous levels, which basically require us to search for the password in a text file. However, the difficulty is that you cannot perform the cat+grep command on it because it is a “binary” file instead of a text file.

This is when you can try out the strings command. Let’s look at the description of the strings command:

The string functions perform string operations on null-terminated strings. See the individual man pages for descriptions of each function.

In short, it goes through the entire file and any string values that it is able to find, it will display it to the output. As per the clue given to us to clear this level, let’s run a strings command on the data.txt file and grep only records with the “=” characters.

bandit9@melinda:~$ strings data.txt | grep "="
epr~F=K
7?YD=
?M=HqAH
/(Ne=
C=_"
I========== the6
z5Y=
`h(8=`
n\H=;
========== password
========== ism
N$=&
l/a=L)
f=C(
========== truKLdjsbJ5g7yyJ2X2R0o3a5HQJFuLk
ie)=5e
bandit9@melinda:~$

The password to gain access to the next level is truKLdjsbJ5g7yyJ2X2R0o3a5HQJFuLk.