Hello Guys!
Today we will discuss the Linux Challenge Walktrought Room on TryHackMe.com
This rooms purpose is to learn or improve your Linux skills.
There will be challenges that will involve you using the following commands and techniques:
Using commands such as: ls, grep, cd, tail, head, curl, strings, tmux, find, locate, diff, tar, xxd
Understanding cronjobs, MOTD's and system mounts
SSH'ing to other users accounts using a password and private key
Locating files on the system hidden in different directories
Encoding methods (base64, hex)
MySQL database interaction
Using SCP to download a file
Understanding Linux system paths and system variables
Understanding file permissions
Using RDP for a GUI
URL: Linux Challenge
Difficulty: Very Easy
Author: Ben
Task 2-1: Garry’s Home Directory
The first Task is to SSH into Garry’s System. We already got the SSH Credentials. In this Case the Command would be the following:
As we can see, there are a Total of 3 Files in his Home Directory.
Task 3: The Basics
Task 3-1: Flag 1
In this Case, the Flag is in our Directory. We simply have to use the Command cat to Display it. In the File we also see the Login Credentials
for the User Bob.
Answer: f40dc0cff080ad38a6ba9a1c2c038b2c
Credentials: bob:linuxrules
Task 3-2: Flag 2
We have the Login Credentials for Bob. We now open a SSH Session with Bob. the Second Flag is located in the /home Directory too.
Answer: 8e255dfa51c9cce67420d2386cede596
Task 3-3: Flag 3
Use ls -la to Display all hidden files and Directorys.
Answer: 9daf3281745c2d75fc6e992ccfdedfcd
Task 3-4: Flag 4
To identify this Flag, we needed a User defined Cronjob Command.
$ crontab -e
Answer: dcd5d1dcfac0578c99b7e7a6437827f3
Task 3-5: Flag 5
We got the Hint to use the find Command, so the Command I used was the following:
$ grep -rw "flag5"
Answer: bd8f33216075e5ba07c9ed41261d1703
Task 3-6: Flag 6
This Flag requires a recursive search Command too. We got the Hint that the first two letters are “c9”.
$ cat /home/flag6.txt | grep c9
Answer: c9e142a1e25b24a837b98db589b08be5
Task 3-7: Flag 7
We got a Hint, we should check the System Processes.
Answer: 274adb75b337307bd57807c005ee6358
Task 3-8: Flag 8
The flag was zipped in a tar.gz format. I had to unzip it using the following Command:
tar -xf flag8.tar.gz
Answer: 75f5edb76fe98dd5fc9f577a3f5de9bc
Task 3-9: Flag 9
The Hosts File is located in /etc/hosts
Answer: dcf50ad844f9fe06339041ccc0d6e280
Task 3-10: Flag 10
We got told to check other Users on the System (passwd).
Answer: 5e23deecfe3a7292970ee48ff1b6d00c
Task 4-1: Flag 11
This Flag was stored in the .bashrc file.
Answer: b4ba05d85801f62c4c0d05d3a76432e0
Task 4-2: Flag 12
The Hint we got, tells us that this Flag is stored where MOTD Files are stored. Thoose Files Display Messages
or even Pictures on the Terminal. Thoose Files are stored under /etc/update-m,otd.d, we are searching for
the 00-header File.
Answer: 01687f0c5e63382f1c9cc783ad44ff7f
Task 4-3: Flag 13
This Requires a different Command.
$ diff flag13/script1 flag13/script2
Answer: 3383f3771ba86b1ed9ab7fbf8abab531
Task 4-4: Flag 14
Logs are mostly stored in the Directory /var/log.
Answer: 71c3a8ad9752666275dadf62a93ef393
Task 4-5: Flag 15
Such Informations can be found in the Directory /etc/*release
Answer: a914945a4b2b5e934ae06ad6f9c6be45
Task 4-6: Flag 16
Mounts are usually displayed in /mount. This one was a bad one.
Answer: cab4b7cae33c87794d82efa1e7f834e6
Task 4-7: Flag 17
We now have to log into the User Alice, her Password is TryHackMe123.
The Flag was right in the /home Directory.
Answer: 89d7bce9d0bab49e11e194b54a601362
Task 4-8: Flag 18
This Flag was just a hidden File.
Answer: c6522bb26600d30254549b6574d2cef2
Task 4-9: Flag 19
To read a specific Line of a File, we will need to use the following Command:
sed -n 2345p flag19
Answer: 490e69bd1bf3fc736cce9ff300653a3b
Task 4-1: Flag 20
This Flag requires to be Base64 Decoded.
$ cat flag20 | base64 --decode
Answer: 02b9aab8a29970db08ec77ae425f6e68
Task 4-2: Flag 21
We will need to inspect the File with less instead of cat since its a .php File.
The File in inside Bob’s Home Directory.
Answer: g00djob
Task 4-3: Flag 22
This Flag is in Hex, we convert it into ASCII with the following Command:
$ cat flag22 | xxd -r -p
Answer: 9d1ae8d569c83e03d8a8f61568a0fa7d
Task 4-4: Flag 23
This Flag is located in /home/alice. it requires a text reverse Command.
$ cat flag23|rev
Answer: ea52970566f4c090a7348b033852bff5
Task 4-5: Flag 24
In order to Display readable Strings, we need to use the following Command:
The Flag is located in the Directory /home/garry.
$ strings /home/garry/flag24
Answer: hidd3nStr1ng
Task 4-7: Flag 26
To find this Flag, insert the Command below.
find / -xdev -type f -print0 2>/dev/null | xargs -0 grep -E '^[a-z0-9]{32}$' 2>/dev/null
Answer: 4bceb76f490b24ed577d704c24d6955d
Task 4-8: Flag 27
We got Permissions to view the File.
Answer: 6fc0c805702baebb0ecc01ae9e5a0db5
Task 4-9: Kernel Version
In order to get the Kernel Version, we use the Command below.
$ uname -a
Answer: 4.4.0-1075-aws
Task 4-10: Flag 29
Follow the Steps below.
$ cat flag29 | tr -d ' ' >flag29_noS
$ cat flag29_noS | tr -d '/n' >flag29_noSN
$ cat flag29_noSN
Answer: fastidiisuscipitmeaei
Task 6-1: Flag 30
In order to get that Flag, I curled localhost.
$ curl localhost
Answer: fe74bb12fe03c5d8dfc245bdd1eae13f
Task 6-2: Flag 31
We got MySQL Credentials. We log in into the MySQL Databse with the following Command:
$ mysql -u root -p
Afterwards we will type in SHOW DATABASES; in order to check all avaible Databases.
Answer: 2fb1cab13bf5f4d61de3555430c917f4
Task 6-3: Flag 31_A
We will now list all the table with the following Commands:
USE database_2fb1cab13bf5f4d61de3555430c917f4
SHOW TABLES;
SELECT * FROM flags;
Answer: ee5954ee1d4d94d61c2f823d7b9d733c
Task 6-4: Flag 32
This Flag requires you to Download the .mp3 File via Filezilla and Listen to it.
Answer: tryhackme1337
Task 6-5: Flag 33
The location to storeee your $PATH is .profile in Bob’s Directory.
Answer: 547b6ceee3c5b997b625de99b044f5cf
Task 6-6: Flag 34
In order to list the enviroment Variables, you will ned to apply the following Command:
$ printenv
Answer: 7a88306309fe05070a7c5bb26a6b2def
Task 6-7: Flag 35
We will use the Command getent group for this one.
Answer: 769afb6
Task 6-8: Flag 36
The Flag is located in /etc. We need to know who i allowed to read it.
$ id
$ cat /etc/flag36
Answer: 83d233f2ffa388e5f0b053848caed1eb