Hacktober 2020 CTF writeup

I played this CTF with my friend from indonesia and in the CTF I solved only 4 challenge because in my country, electricity is down the whole day and some challenges are my teamate solved it,Let’s start with crypto

Crypto

1. Down the wrong path

I got an image with cipher text like this

they gave us a hint

So I know transposition ciphers ,if you don’t know yet , you can read here about that transposition cipher,

It has some method to read . In this photo , It is easy to read, look at this

we can read column by column, see this the first word is REMEMBER , so I write it down and the cipher text gonna be like this ,
REMEMBERTOTELLSPOOKYBOIABOUTTHENEWTARGETSOFOURNEXTATTACK

Let’s make it readable
REMEMBER TO TELL SPOOKY BOI ABOUT THE NEW TARGETS OF OUR NEXT ATTACK

the challenge is only want the name , so the flag is SPOOKYBOI.

Flag : flag{SPOOKYBOI}

Stego

1. Ghost Hunnter

In this challenge , I got an image

the challenge said it has hide information , so I used binwalk and some other tool but it didn’t work, finally I used zsteg and got the flag

zsteg -a ghost_01.png

Flag : flag{8862a805a3140996343da91bdcbda79e}

2.You believe in ghosts?

This one is so easy ,I got a photo in this challenge

And I used stegsolve tool to solve this challenge, change some color and
get the flag :)

Flag: flag{ghosts_everywhere}

3.Start Digging

Also this challenge gave us a photo

The challenge said the flag is hidden

so I used steghide tool , but it didn’t work and then I used binwalk

I got a directory and it has some file

Check with file command what file is this

It all jpg and tiff file ,so change the extension .jpg and the flag have one of the photo

Flag : flag{buried_s3cr3ts}

You can read other challenge from my teamate writeup Inersln

Thanks for reading