what is computer virus ? protect yourself

What is Computer VIRUS?? Protect youself...

WHAT IS A COMPUTER VIRUS ?

A potentially damaging computer
program’s, capable of reproducing
itself causing great harm to files
or other programs without
permission or knowledge of the
user.

TYPES OF VIRUSES :-

1) BOOT SECTOR VIRUS :- BOOT
SECTOR VIRUSES INFECT EITHER
THE MASTER BOOT RECORD OF
THE HARD DISK OR THE FLOPPY
DRIVE. THE BOOT RECORD
PROGRAM RESPONSIBLE FOR THE
BOOTING OF OPERATING SYSTEM
IS REPLACED BY THE VIRUS. THE
VIRUS EITHER COPIES THE
MASTER BOOT PROGRAM TO
ANOTHER PART OF THE HARD
DISK OR OVERWRITES IT. THEY
INFECT A COMPUTER WHEN IT
BOOTS UP OR WHEN IT ACCESSES
THE INFECTED FLOPPY DISK IN
THE FLOPPY DRIVE. I.E. ONCE A
SYSTEM IS INFECTED WITH A
BOOT-SECTOR VIRUS, ANY NON-
WRITE-PROTECTED DISK
ACCESSED BY THIS SYSTEM WILL
BECOME INFECTED.
EXAMPLES OF BOOT- SECTOR
VIRUSES ARE MICHELANGELO
AND STONED.

2) FILE OR PROGRAM VIRUSES :-
SOME FILES/PROGRAMS, WHEN
EXECUTED, LOAD THE VIRUS IN
THE MEMORY AND PERFORM
PREDEFINED FUNCTIONS TO
INFECT THE SYSTEM. THEY
INFECT PROGRAM FILES WITH
EXTENSIONS
LIKE .EXE, .COM, .BIN, .DRV
AND .SYS .
SOME COMMON FILE VIRUSES
ARE SUNDAY, CASCADE.




3) MULTIPARTITE VIRUSES :- A
MULTIPARTITE VIRUS IS A
COMPUTER VIRUS THAT INFECTS
MULTIPLE DIFFERENT TARGET
PLATFORMS, AND REMAINS
RECURSIVELY INFECTIVE IN
EACH TARGET. IT ATTEMPTS TO
ATTACK BOTH THE BOOT SECTOR
AND THE EXECUTABLE, OR
PROGRAMS, FILES AT THE SAME
TIME. WHEN THE VIRUS
ATTACHES TO THE BOOT SECTOR,
IT WILL IN TURN AFFECT THE
SYSTEM’S FILES, AND WHEN THE
VIRUS ATTACHES TO THE FILES,
IT WILL IN TURN INFECT THE
BOOT SECTOR.
This type of virus can re-infect a
system over and over again if all
parts of the virus are not
eradicated.
Ghostball was the first
multipartite virus, discovered by
Fridrik Skulason in October 1989.
Other examples are Invader, Flip,
etc.

4) STEALTH VIRUSES :- THESE
VIRUSES ARE STEALTHY IN
NATURE MEANS IT USES VARIOUS
METHODS FOR HIDING
THEMSELVES TO AVOID
DETECTION. THEY SOMETIMES
REMOVE THEMSELVES FROM THE
MEMORY TEMPORARILY TO
AVOID DETECTION BY
ANTIVIRUS. THEY ARE
SOMEWHAT DIFFICULT TO
DETECT. WHEN AN ANTIVIRUS
PROGRAM TRIES TO DETECT THE
VIRUS, THE STEALTH VIRUS
FEEDS THE ANTIVIRUS PROGRAM
A CLEAN IMAGE OF THE FILE OR
BOOT SECTOR.

5) POLYMORPHIC VIRUSES :-
POLYMORPHIC VIRUSES HAVE
THE ABILITY TO MUTATE
IMPLYING THAT THEY CHANGE
THE VIRAL CODE KNOWN AS THE
SIGNATURE EACH TIME THEY
SPREAD OR INFECT. THUS AN
ANTIVIRUS PROGRAM WHICH IS
SCANNING FOR SPECIFIC VIRUS
CODES UNABLE TO DETECT IT’S
PRESENSE.

6) MACRO VIRUSES :- A MACRO
VIRUS IS A COMPUTER VIRUS
THAT “INFECTS” A MICROSOFT
WORD OR SIMILAR APPLICATION
AND CAUSES A SEQUENCE OF
ACTIONS TO BE PERFORMED
AUTOMATICALLY WHEN THE
APPLICATION IS STARTED OR
SOMETHING ELSE TRIGGERS IT.
MACRO VIRUSES TEND TO BE
SURPRISING BUT RELATIVELY
HARMLESS.A MACRO VIRUS IS
OFTEN SPREAD AS AN E-MAIL
VIRUS. WELL-KNOWN EXAMPLES
ARE CONCEPT VIRUS AND
MELISSA WORM

WAYS HACKERS SEND YOU
SERVER,VIRUSES AND .EXE FILES VIA INTERNET:

1. Binder - Binder is a software
which is used to bind or
collaborate the server or virus you
have created with some other file
like a MP3,JPEG or any other
file.You can fool the victim by
sending him a song or picture and
as soon as he opens the picture or
song the Binder also gets open
and starts working. 

2. Crypter - A crypter is a tool
which changes the binary code of
the .exe (virus,RAT etc.)file and
applies many encryptions on it
which makes the .exe file
undetectable.You can use Chrome Crypter. 

3. Zipping - Another smart way to
send files is by putting your
server in a Zipped folder and then
sending it to the victim.Zipping
the file changes the extension of
the srver from .exe to .zip,which
bypasses the file transfer facility
of gmail,facebook,yahoo etc..
USE WINRAR & Give password of
that file, so AV's not enter in file.

4. Extension - You can change the
extension of the Server you want
to send as it is not possible to
send .exe files,so you can change
the extension of .exe
to .jpeg,.mp3 etc. when you save
the file and then send it to the
victim.But in this method you will
have to tell the victim to change
the extension back to .exe after
he receives the server.This
method can only be used in cases
where the victim is very dumb
and has no knowledge of this
field.
A person who is not much
interested in cyber security should
have knowledge of above
mentioned methods as they can
be used against anyone.