Bandit Level 8 -> Level 9

Level Goal

The password for the next level is stored in the file data.txt and is the only line of text that occurs only once

Commands you may need to solve this level

grep, sort, uniq, strings, base64, tr, tar, gzip, bzip2, xxd

• `sort` is used to output a sorted concatenation of all files to the standard output.
• `uniq` is used to filter out adjacent duplicate lines from the input.

Helpful Reading Material

• Piping and Redirection

 

Write up

bandit8@bandit:~$ ls
data.txt
bandit8@bandit:~$ cat data.txt
riAxnw3RnsFuQiOD8BlZbR6TlERU9866
pJyx6KXXkALfk2n5VSyWS4fqKvnyuN8G
tAw9D85F6PkUdTdlCwmRWYlQNPbkcVox
WWKtMcgokvQfZKjkt2yfJDtMMclL3cMn
fYJtDkXtfgl2A0r3iOlMNrmmCePl568B
.....

 

There is a file where we need to find a word that appears only once, but the content is too long to search manually. This time, we can't use the `grep` command because we don't know a specific pattern to match. However, we have a clue: the text appears only one time. 

 

bandit8@bandit:~$ uniq -c data.txt
	1 riAxnw3RnsFuQiOD8BlZbR6TlERU9866
	1 pJyx6KXXkALfk2n5VSyWS4fqKvnyuN8G
	1 tAw9D85F6PkUdTdlCwmRWYlQNPbkcVox
	1 WWKtMcgokvQfZKjkt2yfJDtMMclL3cMn
	1 fYJtDkXtfgl2A0r3iOlMNrmmCePl568B
	.......

 

The `uniq` command is suitable for this challenge. By using the `-c` option, we can see how many times each line occurs. However, since `uniq` only filters adjacent matching lines, we need to sort the file first to make it effective.

 

bandit8@bandit:~$ sort data.txt | uniq -c
	10 0KCctkqCfY7BIOWqolXsHDaboXVTKZ49
	10 1SKCEfQ151hWOx9JkeIAmOQdXiC813h1
	10 3hHLofjM7m3sdyiKJF5QsMqvEIfFh5b1
 	10 3hW8tLnDV8acjhTQi44CKXEzHsJb3sqz
	10 3nUXvAjKo7yu6fYykYu7nGGKDMuNMWZf
	10 42qjuz5hdLlItNwdJYsDRpkbbvoEYiWK
	 1 4CKMh1JI91bUIZZPXDqGanal4xvAg0JM
	10 5g2sV4OokwqDv29Pfo6C7twjKcOk4WQV
	10 5YlL2xxyEUqV6tF0P6NoHt8LOY2EGEcO
	10 6lMDNhQjlOoCOZ5F8ULK2g0uT0rCdnoQ
	......

bandit8@bandit:~$ sort data.txt | uniq -u
4CKMh1JI91bUIZZPXDqGanal4xvAg0JM

 

We can utilize the `uniq` command in two ways. First, by using the `-c` option to check how many times each line occurs. Second, by using the `-u` option to print only the unique lines. This will help us find the password!

 

 

Next Level : Level 9 -> 10