PicoCTF 2017 – Hex2Raw

Another day, another challenge…

Today’s challenge we will be solving the Hex2Raw challenge in the PicoCTF.

Let’s start.

Clicking on the challenge we see the following:

OK. With this challenge we see that we need to print unprintable characters from the following location.

Let’s see what the hints give us.

Clicking on the hints we see:

OK. We can see that Google has easy techniques to do this.

Let’s go to the command line and see what we can do.

After logging in and going to the directory we see the following:

Running the hex2raw application we see:

I pressed Ctrl + C to end the program.

OK. We are given raw input and we need to convert it to hexadecimal character.

Doing a Google search we noticed that we can use Python to get our desired output.

How would we do this?

With the decode function!

Explaining the screenshot below we’re invoking the python interpreter the -c designated that we’re using a command. We’re printing the raw form, and using the decode function designated that we wanted to decode with the hexadecimal system. We’re going to pipe the output to the hex2raw program.

Doing this we see the flag, and acquired 20 points!