Hack the d0not5top VM (CTF Challenge)

This time we are going to solve a fun Vulnerable Lab d0not5top 1.2. To do so we are going to download the VM Machine from here.

The credit for developing this VM machine is going to 3mrgnc3 who has hidden 7 flags inside this lab as a challenge for hackers.

Let’s Breach

As always, Let us start form getting to know the IP of VM (Here, I have it at 192.168.1.113 but you will have to find your own)

Next, we run nmap

Now, visit the IP in the Browser.

Since I didn’t found something interesting when exploring it’s IP in the browser, therefore now I am going to scan the Web Content by using dirb in Kali Linux.

As you can observe from above the image I have highlighted a URL which indicates the control panel of the website. Let’s open 192.168.1.113/control in the browser. Yes, it is DNS control panel but I didn’t find any clue for the 1st flag on this web page.

After that move towards its view source page and notice FL46_1 which indicates that it is the 1st flag.

Wonderful!! Successfully found the 1st flag

From the scanning result of dirb we found so many web directories in this machine, therefore further I chose 192.168.1.113/control/js directory. In this directory, I found a file README.MadBro. It will open as shown below.

 Now here we found a binary code which is to be converted into decimal. On conversion we found FL46_2:30931r42q2svdfsxk9i13ry4f2srtr98h2

Great!! Successfully got 2nd Flag.

Now, for the third flag, we will use netcat very verbose mode on port 25 which hosts smtpd service (This can be found by doing an aggressive nmap scan on the IP)

Here we found a Hexadecimal code which is to be converted in Text.

Great!! Successfully got 3rd Flag also.

On the URL where we found Second Flag, there is an instruction written in Leet, It reads: M4K3 5UR3 2 S3TUP YOUR /3TC/HO5TS N3XT TIM3 L0053R… 1T’5 D0Not5topMe.ctf!!! So we will go to /etc/hosts and add an entry as shown in the given image.

Now open donot5topme.ctf in the browser as shown and Click on Register has given at the end of the web page.

As you can observe that we didn’t found any clue on this web page, therefore, opened the source code of the page.

At View Page Source, here we found this link as shown in highlighted text.

I googled this encoding. It is known as brain fuck encoding.

So we will decrypt it. Here we got the FL46_4

Successfully found the 4th flag

Now move back to the d0not5topme.ctf. Now we will click on Register and Then on I agree to these terms and we will get to Registration Page. Here we click on Board Administration, which opens a prompt which asks for the client to open mailto link, here I choose Gmail.

Here I found another ctf “[email protected]

Now let’s add G4M35.ctf into /etc/hosts as we did before and click on Save.

When I open this domain in the browser, I got a game to play, although you can get the next clue by playing too, but I  thought of a more technical approach and opened this web page with Inspect Element. Now select the Debugger Tab. Here I found game.js and inside the Game_Over script I found the next clue as “/H3X6L4m3

After opening the complete link “g4m35.ctf/H3X6L4m3” on this domain it gave me another game.

Again we can play and discover the next clue/flag. But we went to get a bit technical approach and ran a dirb command to look after it’s directories.

From the given result I had highlighted //g4m35.ctf/H3x6L64m3/textures/ for further enumeration.

Now I have opened this textures directory in the browser, here I opened the skybox directory and then the dawnclouds directory and found the nz.jpg file as shown.

After opening this image I got the octal code.

After decoding this code I found FL46_5

I Captured the 5th flag also!!

Now get back to the second game //g4m35.ctf/H3x6L64m3 and open with Inspect Element. Now select the Debugger Tab. Here I found Gameplay.js and got another domain “t3rmln4l.ctf” as shown below.

Now let’s add t3rmln4l.ctf into /etc/hosts as we did before and click on Save.

Now as before, while opening this domain in the browser, I got a terminal which asks for a password. After trying a bunch of commands, I found grep* runs on this terminal and for authentication, I entered the name of the domain as password i.e t3rm1a4l.ctf and found another domain “M36u574.ctf”.

Now let’s add M36u574.ctf into /etc/hosts as we did before and click on Save.

Now as before, you will open this domain in the browser, you will get a slideshow of Megusta images. Out of multiple images, I downloaded the kingmegusta.jpg.

 Now we will run exiftool on this image, here I got some code in Comment as shown below.

After converting the code to the text I found the following code as shown in the image. It is base64 encoded.

Then I created a text file on /root/Desktop/ and pasted the above-decoded text in this file.

By running John The Ripper, using this file as shown

I found a user MeGustaKing and Password ********** (10 times *).

Now using this username and password combination we will login into the ssh. Here we get a code and another username and password combination i.e. burtieo: Lets you update your FunNotes and more! But first, let’s decode the highlighted code.

Copy and paste above code inside it. It is in base64 encryption, after decrypting the code we found that it is md5 encoded.

Great! It is the 6th Flag.

As mentioned above in the previous ssh login we got this username burtieo and its password is the text written above it i.e. Lets you update your FunNotes and more!

Now let’s login in ssh using a combination

Username: burtieo and Password: Lets you update your FunNotes and more!

This opens rbash shell and rbash shell restricts some of the features of the bash shell.

So, firstly run following command

And then run the command

Using nmap command I found the port 10000 is open.

But this port only remains open for 20 seconds, we can make it stay open for long using “for loop” as shown.

Now let’s run Metasploit and use the exploit named file_disclosure

I found the RSA Private Key as shown.

 

Now copy and paste this Private Key in a file and name it id_rsa and then run John The Ripper.

This has given the root password .i.e. “gustateamo

Now I have removed permissions of id_rsa by chmod 700 and logged in into ssh as root with password gustateamo as shown below.

Now type the following command

You can observe from the given image that it consists of two files. Let’s open one of them.

Here it gave the message to use L45T_fl46.pl

Now use netcat command to establish a connection with the target through port 1234.

Now in D0Not5top terminal, we will open file L45T_fl46.pl with IP 192.168.0.7 (Kali Linux IP) as given below:

On attacker system it will you will found get netcat to connect with the targeted system. The highlighted text is indicating toward FL46_7

Congratulations!! It’s the 7th Flag.

Solving this lab was fun and a great experience.

Author: Benoy Naskar is a Certified Ethical Hacker, Cyber Security Expert, Penetration Tester. contact here

Leave a Reply

Your email address will not be published. Required fields are marked *