EncryptCTF 2019 Some Challenges Writeups

Forensics

It’s a WrEP
Wi Will H4CK YOU

Steganography

Into The Black
yhpargonagets

It’s a WrEP

In this question, sniffed packet of wep network is given and we have to find the key of encryptCTF wifi network. I immediately think that wep is insecure and if we can analyse the sniffed pcap file using aircrack-ng tool(One of the awesome tool for network) then we will get the password of encryptCTF wifi network.

I run

 aircrack-ng encryptCTFWEP.cap 

command in my terminal. It asks for network index from given network in that file. Now index 3 is for encryptCTF wifi.

Type 3 and press enter you see the password(

 W45_17_R34L?!

).

 Flag:encryptCTF{W45_17_R34L?!} 

Wi Will H4CK YOU

This question is similar than It’s a WrEP question but file contain WPA network sniffed packet. Again we have to analyse the give pcap file with aircrack-ng tool but this time we have to use wordlist to bruteforce the password.

Run

 aircrack-ng encryptCTFWPA.cap -w rockyou.txt 

command (rockyou.txt is worldlist) in your terminal. Again asking for network index this time type 1 and it takes some time to bruteforce the password and finally you left with

 ThanckYou 

which is the password.

Flag: encryptCTF{ThanckYou} 

Into The Black

We have a image file.

It’s a one of the easy question. Simply use

 Stegsolve 

tool to see other plane of given image. In Red plane 1 flag is written.

 Flag:encryptCTF{L1GH7_17_UP} 

yhpargonagets

We have given a image file with jpg extension but when you see the type of file using file command in linux, you found that given file is a png image. You change the extension of image but you can’t find anything there. Challenge name is a hint, reverse the name of challenge. Steganography is a pip. You have to install steganography pip in your machine. After that simply run

 steganography -d encoded.jpg 

(-d to decode the image) command in your terminal which decode the image file into the flag for this challenge.

Flag: encryptCTF{pip_in5t411_5teg4n0graphy}