Wednesday 29 August 2018

CTFlearn - BOOK REPORT

https://beta.ctflearn.com/problems/99

Cryptography

natjef20

Python 3x

str=['muffins','safetydance','updateerror','tracebackerror','abcdefghijklmnopqrstuvwxyz','wowneatocool','great','filefolders','goodnessgraious','tombstone','aidanglickman','qwertyuiopasdfghjklzxcvbnm','ABCTFLearn','CornOnTheC*ob*','le14{octobre}','cryptogra\?!FRE"GCN"E','BJblazkowicz','red_HeRRiNGG<>TIME!']

printIndex= [(13,1),(17,3),(14,10),(18,18),(16,13),(15,5),(5,6),(12,8),(8,3),(2,5),(4,10),(11,3),(1,5),(10,1),(7,5),(6,10),(9,4),(3,10),(15,13)]

rtn=['']
for word in str:
  rtn.append(list(word))

result=""
for x,y in printIndex:
  result+=rtn[x][y-1]

print(result)

The result is not AbCEF{filtedittodo} , there are two spelling mistakes.

Useful link
https://repl.it/

CTFlearn - FRIEND JOKE..

https://beta.ctflearn.com/problems/554

Cryptography

kholoud

Tips: BASE64 encoding

d2lzaF95b3VfaGFwcHlfZGF5

Useful Link

https://www.asciitohex.com/

CTFlearn - ANCIENT CIPHER

https://beta.ctflearn.com/problems/550

Cryptography

andreigasparovici

Tips: This is Rail Fence (Zig-Zag) Cipher (3 level)

The rail fence cipher is a form of transposition cipher. It derives its name from the way in which it is encoded

ILYWOYFNYRPOASESOCTSA

Useful link

https://www.dcode.fr/rail-fence-cipher

Tuesday 28 August 2018

CTFlearn - 07601

https://beta.ctflearn.com/problems/97
Forensics
by alexkato29

1) Download the image and vi the AGT.png. you will find the header JFIF which stands for stands for JPEG File Interchange Format.

$ vi AGT.png

2) Used strings to check the image AGT.png, you will get the following result. It looks like a zip instead of JPEG file

$ strings AGT.png

3) Used binwalk to inspect AGT.png. This is what I got.

$ binwalk AGT.png

4) Extract the file

 $ binwalk -e AGT.png

5) Follow the tips, find the image file "I warned You.jpeg"

 Secret Stuff.../Don't Open This.../I Warned You.jpegUX

6) Used strings the image and you will find the flag

CTFlearn FORENSICS 101

https://beta.ctflearn.com/problems/96

The image contains the flag string, you can just open the image using any editor and read line by line to find the flag.

But there is a smart way using the "strings" command

Monday 27 August 2018

CTFlearn - BASIC INJECTION

https://beta.ctflearn.com/problems/88

Step 1
Ensure that this web is SQL injectable, using this input a' or '1'='1

Step 2

This is the answer:

Usable Resource for SQL Injection

https://pentestlab.blog/2012/12/24/sql-injection-authentication-bypass-cheat-sheet/
https://www.netsparker.com/blog/web-security/sql-injection-cheat-sheet/

Remotely getting the Chrome Browser's encrypted password file

Background

Chrome browser using a win32 API win32crypt.CryptProtectData and win32crypt.CryptUnprotectData to encrypt and decrypt the "reminder" password DB in sqlite respectively, this file saved at c:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Login Data

Tools:

OS: Kali

Language: Python 3

Target Client OS: Window 10 Professional, with the latest patch and anti-virus enabled

Steps

1) the Python HTTP Server started up at Kali Linux

2) a Python Malware Client (PMC) got a single from a Twister Account "fkclai" to start the attack

3) this PMC sent an HTTP Get request to Kali HTTP server

4) the server returned a post request with commend "showChromePwd" to instruct the PMC return the Chrome Browser Password

5) the PMC got the password file and decrypted it using win32 API and returned the result

6) Kali HTTP server display the result at the console

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as of 28 Aug 2018

https://beta.ctflearn.com

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