Feeds:
Posts
Comments

Archive for May, 2020

In this tutorial I will show you how to read data from Arduino Uno using pySerial library from Python and visualize it into Live Plot graph.
I assume that you have already familiar with Matplotlib. If not, you can read my article about it.

What you need?
Arduino Uno (you can use other type).
-Temperature sensor LD35
USB connector
-3 small cable

Before we start you have to make sure that you have already installed python libraries below:
Matplotlib
pySerial
drawnow

Since I have already Matplolib library, I just need to install Pyserial and Drawnow.

$ pip3 install pyserial
Collecting pyserial
Downloading 
https://files.pythonhosted.org/packages/0d/e4/2a744dd9e3be04a0c0907414e2a01a7c88bb3915cbe3c8cc06e209f59c30/pyserial-3.4-py2.py3-none-any.whl (193kB)
100% |████████████████████████████████| 194kB 30kB/s
Installing collected packages: pyserial
Successfully installed pyserial-3.4
$

Before you install ‘drawnow’ library, you have to install ‘html5lib==1.0b10’ first.

$ pip3 install html5lib==1.0b10
Collecting html5lib==1.0b10
Downloading 
https://files.pythonhosted.org/packages/2f/747793ca2d36f676b740efc04b7ba887c610119beb5841d1805cb3515616cb/html5lib-1.0b10-py2.py3-none-any.whl (112kB)
100% |████████████████████████████████| 112kB 11kB/s
Collecting webencodings (from html5lib==1.0b10)
Downloading 
https://files.pythonhosted.org/packages/f4/24/2a3e3df732393fed8b3ebf2ec078f05546de641fe1b667ee316ec1dcf3b7/webencodings-0.5.1-py2.py3-none-any.whl
Collecting six (from html5lib==1.0b10)
Using cached https://files.pythonhosted.org/packages/65/eb/1f97cb97bfc2390a276969c6fae16075da282f5058082d4cb10c6c5c1dba/six-1.14.0-py2.py3-none-any.whl
Collecting setuptools>=18.5 (from html5lib==1.0b10)
Downloading 
https://files.pythonhosted.org/packages/a0/df/635cdb901ee4a8a42ec68e480c49f85f4c59e8816effbf57d9e6ee8b3588/setuptools-46.1.3-py3-none-any.whl (582kB) 100% |████████████████████████████████| 583kB 107kB/s Installing collected packages: webencodings, six, setuptools, html5lib Successfully installed html5lib-1.0b10 setuptools-46.1.3 six-1.14.0 webencodings-0.5.1 
$

Now, you can install drawnow library

$ pip3 install drawnow
Collecting drawnow
Using cached https://files.pythonhosted.org/packages/8b/bc/3a0238eb1e6222b4e2c74fcd171453d714e2f67c0f224fd5160d83636e10/drawnow-0.72.0-py3-none-any.whl

Collecting matplotlib>=1.5 (from drawnow)
Downloading 
https://files.pythonhosted.org/packages/93/4b/52da6b1523d5139d04e02d9e26ceda6146b48f2a4e5d2abfdf1c7bac8c40/matplotlib-3.2.1-cp36-cp36m-manylinux1_x86_64.whl (12.4MB) 100% |████████████████████████████████| 12.4MB 57kB/s Collecting python-dateutil>=2.1 (from matplotlib>=1.5->drawnow) Using cached https://files.pythonhosted.org/packages/d4/70/d60450c3dd48ef87586924207ae8907090de0b306af2bce5d134d78615cb/python_dateutil-2.8.1-py2.py3-none-any.whl 

Collecting kiwisolver>=1.0.1 (from matplotlib>=1.5->drawnow)
Downloading 
https://files.pythonhosted.org/packages/ae/23/147de658aabbf968324551ea22c0c13a00284c4ef49a77002e91f79657b7/kiwisolver-1.2.0-cp36-cp36m-manylinux1_x86_64.whl (88kB) 100% |████████████████████████████████| 92kB 115kB/s 

Collecting numpy>=1.11 (from matplotlib>=1.5->drawnow) 
Downloading 
https://files.pythonhosted.org/packages/3d/fc/4763e5f17ac6e7e7d55f377cde859ca1c5d5ac624441ab45315bc578aa9e/numpy-1.18.3-cp36-cp36m-manylinux1_x86_64.whl (20.2MB) 100% |████████████████████████████████| 20.2MB 44kB/s Collecting cycler>=0.10 (from matplotlib>=1.5->drawnow) 
Using cached https://files.pythonhosted.org/packages/f7/d2/e07d3ebb2bd7af696440ce7e754c59dd546ffe1bbe732c8ab68b9c834e61/cycler-0.10.0-py2.py3-none-any.whl

Collecting pyparsing!=2.0.4,!=2.1.2,!=2.1.6,>=2.0.1 (from matplotlib>=1.5->drawnow)
Downloading 
https://files.pythonhosted.org/packages/8a/bb/488841f56197b13700afd5658fc279a2025a39e22449b7cf29864669b15d/pyparsing-2.4.7-py2.py3-none-any.whl (67kB) 100% |████████████████████████████████| 71kB 169kB/s Collecting six>=1.5 (from python-dateutil>=2.1->matplotlib>=1.5->drawnow) Using cached https://files.pythonhosted.org/packages/65/eb/1f97cb97bfc2390a276969c6fae16075da282f5058082d4cb10c6c5c1dba/six-1.14.0-py2.py3-none-any.whl 
Installing collected packages: six, python-dateutil, kiwisolver, numpy, cycler, pyparsing, matplotlib, drawnow Successfully installed cycler-0.10.0 drawnow-0.72.0 kiwisolver-1.2.0 matplotlib-3.2.1 numpy-1.18.3 pyparsing-2.4.7 python-dateutil-2.8.1 six-1.14.0 
$

There are 2 things that we will do:
-first, program your Arduino to send the temperatur data through serial port.
-second, program python to read the data and display it.

(more…)

Read Full Post »

What is shellcode?
Shellcode is a set of instruction written in machine code which is generally used as payload in the exploitation of software vunerability. Since it starts with command shell that’s why it is named as Shellcode.

It’s the sampel of shellcode:
“\x48\x65\x6c\x6c\x6f\x20\x57\x6f\x72\x6c\x64\x21\x0a”

It stands for ‘Hello World!’.

For writing shellcode, you must familiar with Assembly Language programming and target hardware architecture. You can’t write shellcode for 32bit architecture and run in it 64bit architecture because the instruction codes that are loaded into the memory layout is also different.
If you write a program with c language, run it in 32bit architecture, the instruction codes will be loaded above stack but in 64bit it will be loaded above the heap.
It depend also on Operating System used. That’s why shellcode is designed for specific target system that take advantages its vulnerability.

Efficiency is needed when you wrote shellcode because it related with the size of buffer.

In this tutorial, I run the shellcode under Linux Ubuntu 18.04.4 LTS 32 bit in docker container. My hardware architecture is AMD ryzen 64bit. For programming I use gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0 for compiling c code, NASM version 2.13.02 for compiling assembly code and GNU objdump (GNU Binutils for Ubuntu) 2.30 for display machine code.

Writing shellcode also a bit tricky.

I give you an example.
Below is the assembly code to display “hello word!”.
Assembly code 1 (hello1)

1 section .text
2 global _start
3
4 _start:
5
6  ;Display Message
7  mov eax,4 ;syswrite=4
8  mov ebx,1 ;stdout=1
9  mov ecx,msg
10 mov edx,lenmsg
11 int 0x80 ;System Call
12
13 ;Exit
14 mov eax,1
15 mov ebx,0
16 int 0x80
17
18 section .data
19 msg db 'Hello World!',0xa
20 lenmsg equ $ - msg
I compile and run this code.
root@fc9fca692021:/home/darklinux# nasm -f elf32 hello1.asm -o hello1.o
root@fc9fca692021:/home/darklinux# ld hello1.o -o hello1
root@fc9fca692021:/home/darklinux# ./hello1
Hello World!
root@fc9fca692021:/home/darklinux#

It runs perfect.

(more…)

Read Full Post »