Hacktober CTF 2020 Beginner Writeup

I'm a beginner, and this is my 6th CTF. I post what I do, and I think this will help someone.

Ask questions from me, teach me something that I posted wrong, or any other ways you solved these challenges in the comment section.

Start

Rules 1

Challenge

Solution

Copy and paste flag as it says

Flag : flag{pl4y_by_th3_ru13s}

DEADFACE 1

Challenge

Solution

On the home page of Hacktober CTF, there is a link near the "Rules" link called "Intel" that goes to "http://ctf.cyberhacktics.com/intel". There shows a hacker group called "DEADFACE" and its affiliates and in that profile, shows a data called "Threat"; In this challenge, we should do count how many DEADFACE Affiliates on that page. And submit it as a flag.

Flag: flag{7}

After these challenges have been done "Let's Begin!" challenges appear.

Let's Begin!

Challenge

Solution

Copy and paste flag as it says

Flag : flag{lets_get_started}

DEADFACE 2

Challenge

Solution

While reading the Intel page, we can find this profile. Almost all hackers didn't use their real name as any of Usernames then we can think that "mort1cia" is the username of this profile.





Flag : flag{mort1cia}

Programming

Message in an Array

Challenge

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace GhostTown

{

    class Program

    {

        static void Main(string[] args)

        {

           string[] str = new string[4] {"DEADFACE","Nothing", "Stop", "Will"};

           Console.WriteLine("{1} {3} {2} {0}", str);

         }

    }

}

Solution

I don't know which programing language is this, but I know how array works. I thought that 

{1} = "Nothing"

{3} =  "Will"

{2} =  "Stop"

{0} =  "DEADFACE"

and I placed them as the instructions say.

Flag: flag{Nothing Will Stop DEADFACE}

Trick or Treat

Challenge

Download File

Solution

I never run any code before looking into source because of past experience. After I opened this python file in Notepad++, I see that it called to wrong function, and I fixed it. Also, that function only returns the flag.

Fixed code with Treat

Flag : flag{2f3ba6b5fb8bb84c33b584f981c2d13d}

Cryptography

Hail Caesar!

Challenge

Download Image

Solution

It is a Caesar Cypher. It is in the name of the challenge, and I think the image is another clue to lead you to that. I didn't see any other clue on this image. You can decode this with hand or online Caesar Cypher decoder. I used this site and used the brute-force method.


Flag: flag{BOO SCARED YOU}

Linux

Talking to the Dead 1

Challenge

Solution

First Ssh into the server using command and password

Then I go to the Home directory of the current user and go to the Documents folder.

There I found the "flag1.txt"

Flag : flag{cb07e9d6086d50ee11c0d968f1e5c4bf1c89418c}

Talking to the Dead 2

Challenge

Challenge description says that the flag is owned by the same user and it is a hidden file, named "flag2.txt".

"ls" command only shows the normal files I use the option "-a" to get hidden files with list.