This document defines malware and describes common types like viruses, trojans, and spyware. It then focuses on viruses, explaining that they are small programs that alter computer operations without permission. Viruses can replicate themselves and spread to other computers or removable media. The document classifies viruses and provides examples like boot sector, master boot record, file infector, and macro viruses. It discusses some advantages and major disadvantages of viruses, and lists the top 10 most destructive computer viruses.
2. What Is Malware?
Malware: ( stands for Malicious Software ), some times referred as ‘Pestware’.
Malware is a software designed to harm or secretly access a computer system
without the owner's informed consent.
Malware is a software program designed to harm, secretly access or get into a
computer system, without any user’s acknowledgement.
4. Lets Introduce The Common Ones...
VIRUS:
A computer virus is a small program written to alter the way a
computer operates, without the permission or knowledge of the user.
Have the ability to replicate itself, thus continuing to spread.
Also, known as Malicious Software, a program that can cause damage to a computer.
The computer viruses can damage or corrupt data, modify existing data, or degrade the
performance of the system by utilizing resources such as memory or disk space.
5. It may spread over a network (internet), carried
through removable medium such as a Floppy
disk, CD/DVD Drive, USB Drive.
The main two characteristics of a
VIRUS are:
It can replicate itself.
It has the ability to spread itself to other files as well to other computers.
6. Classification of Computer viruses:
•Boot sector virus
•Master Boot Record (MBR) virus
•File infector virus
•Multipartite virus
•Macro virus
7. BOOT SECTOR VIRUS:
Boot sector viruses generally hide in the boot sector, either in the
bootable disk or the hard drive.
Infects the boot sector of computers. During system boot, boot
sector virus is loaded into main memory and destroys data into
hard drive.
8. MASTER BOOT RECORD VIRUS:
MBR viruses are memory-resident viruses that infect disks in the same
manner as boot sector viruses. However it, infects the MBR of the system,
gets activated when the BIOS activates the Master boot code.
MBR infectors normally save a legitimate copy of the master boot record in
an different location.
9. File Infector Virus:
File Infector viruses infect program files.
Normally infect executable code, such as .COM, .SYS, .BAT and .EXE files.
They can infect other files when an infected program is run from floppy, hard drive, or from
the network.
Many of these viruses are memory resident. After memory becomes infected, any
uninfected executable file that runs becomes infected.
E.g. Snow.A, Jerusalem, Cascade
10. Macro Virus:
Macro are mini-programs which make it possible to automate series of operations so that
they are performed as a single action, thereby saving the user from having to carry them out
one by one.
Macro viruses infect files that are created using certain applications or programs that
contain macros.
They are platform-independent since the virus itself are written in language of the
application and not the operating system.
They infect documents created from Microsoft Office Word, Excel, PowerPoint and Access
files.
E.g.W97M.Melissa, Bablas, WM.NiceDay, W97M.Groov
11. Advantages of VIRUS
A virus is able to take control of a person's computer.
Warning,, its illegal..!!
But can be used in order to get full record of doubted person’s activity.
Computer viruses are also considered an important part of technological warfare. For
example, Iran has accused several countries of targeting (and successfully shutting
down) their illegal nuclear facilities, using computer viruses.
Through computer virus we can inject a virus into a computer that is trying to affect our
system.
Viruses can be written to take advantage of a particular program or operating system's
features so as to make it more likely that they will
be inadvertently run.
Viruses can handle Multiple Instructions.
They can broadcast itself.
12. Dis-advantages of VIRUS
May damage hard ware - Usually Bios, hard disk etc.
Loss of Software Functionality.
Some the applications won't start (ex: I hate Mozilla virus won't let you
start the Mozilla)
Your computer gets slowed down.
Replicates itself without any permission.
No guarantee of your Privacy, can be easily accessed, modified by
anyone, anytime and anywhere.
13. Top 10 Most-Destructive Computer Virsues..
Created by underground crime syndicates and government agencies,
these powerful viruses have done serious damage to computer networks
worldwide
1) Stuxnet (2009-2010)
2) Conficker Virus (2009)
3) Agent.btz (2008)
4) Zeus (2007)
5) PoisonIvy (2005)
6) MyDoom (2004)
7) Fizzer (2003)
8) Slammer (2003)
9) Code Red (2001)
10) Love Letter/I LOVE YOU (2000)