Presentation by Mohak

8/13/2019 Presentation by Mohak

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At

GlanceWhat is Virus?

Hackers &Crackers

Types ofComputer

VirusesSome other

HarmfulPrograms

How youProtect your

System

againstViruses ?


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A virus is a program that enters thecomputer system by attacking itself to

another program and then spreads itselfacross the system.


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There are two different types of people who write

computer virus programs

Hackers

Crackers

Hackersrefers to the people who use their skills to enter into

computer system without authorization. Hackers are

computer enthusiasts, who break into secure systems to gain

knowledge about them and possibly use their knowledge toplay pranks.

A Crackeris malicious programmer who gain unauthorized

access to computer system for the purpose of stealing,altering or corrupting information.


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There are so many types of computerviruses.

Some of them are : Macro VirusFile Infector

Resident VirusNetwork Virus

Logic omboot Sector Virus

Multipartite VirusStealth Virus


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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 elsetriggers it. Macro viruses tend to be surprising but

relatively harmless. A typical effect is the undesired

insertion of some comic text at certain points when

writing a line. A macro virus is often spread as an e-mail virus. A well-known example in March, 1999 was

the Melissa virus virus.


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Phrasp the most common type of virus, the file infector

takes root in a host file and then begins its operation

when the file is executed. The virus may completelyoverwrite the file that it infects, or may only replace

parts of the file. Some file infector viruses attack

themselves to program file, usually selected .COM or

.EXE file.


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A board virus definition applies to any

virus that inserts itself into a systemsmemory


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A kind of virus spreads across networks in computers,

for example, Nimda and SQL SLAMMER worms are

viruses which spread over corporated networks or theinternet via e-mails.


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A logic Bomb is a program that get executed only

when specific condition is met. The virus: Friday the

13th,, was so programmed so as to get executed on

that perticular date.


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A boot sector virus hides in the boot sector of hard

disk. The boot sector is where your operating

system is. So every time you boot your computer

the virus gets loaded into the computer memory.

Examples of boot-sector viruses are Polyboot B,

AntiEXE.


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This virus is spread by infected floppies and CDs.

These viruses first infect the boot sector of hard drive

and then infect the executable files stored in it. For ex.-

Ywinz.


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These are some virus which try to hide

themselves from Anti-virus software byresorting some tricks. Stealth virus can

safely show an anti-virus software that a

certain file is uninfected.


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A Trojan Horse program is a file that appears

harmless unless it has executed. The Trojan Horse

program disguises itself as a game or a utility

program but when executed it can destroy the data

stored in the computer. The name Trojan Horse hasbeen derived from Greek mythology.


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Worms are small pieces of software that use

computer network and security holes to replicateitself.

Worms on the internet spread by e-mail it

searches for all the address book of the mailing

system. It then mails to all recipients.


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Install a good Anti-Virus software on your computer.

Update Anti-Virus regularly.

Be careful while Downloading files or programs from the

internet.


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PresentedBy

Guided By : Vandana Maam

Documents

Presentation by Mohak