introductio to virus

“VIRUS..”

SARMAD SOOMRO 2K12/IT/72

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.

Types Of Malwares

Virus Trojan Horse Spyware Adware Rootkits Crimeware Scareware

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.

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.

Classification of Computer viruses:

•Boot sector virus

•Master Boot Record (MBR) virus

•File infector virus

•Multipartite virus

•Macro virus

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.

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.

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

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

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.

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.

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)

References…

https://sites.google.com/site/drzeeshanacademy/system-administrationhttp://technology.blurtit.com/784117/what-are-the-advantages-of-computer-viruseshttps://answers.yahoo.com/question/index?qid=20081210042930AAWFf52

http://www.smithsonianmag.com/science-nature/top-ten-most-destructive-computer-viruses-159542266/#0yHrMQjH3vJOqwuv.99