system security ppt.pptx

7/28/2019 system security ppt.pptx

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Now a days , there are so many unethicalpractices in the form of digital attacks whichare causing problems in the form of

Information Technology . These attacks aresometimes in the form of malicious softwarewhich enter in the system by themselveswithout the knowledge of user and sometimesin the form of an unauthorized user who getthe access to computer system for damagingthe stored data , to steal information or to

keep the eyes on the activities of computer .Some of the common forms of digital attacksare: Computer Virus , Spam , Phishing ,Spyware , Adware , Hacking , Cracking , etc.


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MALWARE

Malware stands for MaliciousSoftware . It is a general term used torefer any kind of digital attacks onthe computer system .It is a kind ofunwanted software which is stored in

your system by someone else toperform malicious functions .


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Malware can be divided intonumber of different categories

which include :Computer Virus

Spam

AdwareSpyware

Worm

Trojan HorseLogic Bomb


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Computer VirusComputer viruses are in fact the malicious

programs having the ability to replicate andexecute themselves . They can attachingthemselves to the other programs , files or data

stored in the system automatically without anyinstructions from the user . It can enter into theother computer by different means like when youcopy some data from an infected system to another

system or it can come to your system as an e-mailmessage . Once entered into the system itautomatically attaches itself to the system files of

your computer .


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TYPES OF COMPUTER VIRUSBased upon their work , computer viruses

can be of different types:Worm

Trojan

BombBased upon their target infection it is ofvarious types:

Boot VirusProgram Virus

Macro Virus

Stealth Virus


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WORMThese are very sophisticated viruses with

the ability to spread very quickly . Normally,these viruses does not cause any harm to the

system , but they just keep on replicating

themselves to the discs used in the system orthrough network they keep on spreading to

the other systems . They reduce the storage

space and available memory of the system ,e.g. , Scalper , Morris Worms .


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TROJANTrojans are those destructive programs that

hide its intention as they appear to be theuseful utilities . These types of viruses oftencome to you as e-mail attachments with

fascinating names forcing you to open them .They start deleting files in the system . Theyspread by copying to the other systems ,

e.g. , Backdoor .


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BOMBThese types of viruses remain inactive and

undeleted in the system for a long time andwait for a specific event or date to trigger . For

example , Israeli Virus or Friday 13th Virus

waits for Friday the 13th , and deletes theprogram files on that day .Saturday 14th ,

Tuesday the 13th, etc. are the other examples.


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BOOT VIRUSThese types of viruses infect the Master

Boot Record {MBR} of the hard disc driveor DOS boot record {DBR} of the floppydisc . Every time a system is booted with

an infected hard disc or floppy disc ,these viruses become active and startinfecting the stored data . Danish boot ,

PC stone , Joshi are the examples of bootvirus .


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PROGRAM VIRUSAlso known as the Parasitic viruses , they infect

the program files of your system having extensionname as .COM , .EXE , .SYS , .OVL , .DLL , .SCR ,etc . These viruses do not affect the boot recordsof the system . Program files are their attractivetargets because these files are used veryfrequently and moreover the format of these filesis quite simple . So , when these programs are

used they become active in the memory ofcomputer and start its destruction work .


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MACRO VIRUSThe main target area of these categories of viruses

is to infect the data of your system . Whenever youwork with the applications like MS-Word , MS-EXCEL , etc . You save some important data in the

shape of files . These type of viruses destroy thedata stored by you causing irrecoverable damagesometimes .They can easily spread from onecomputer to another on the network or throughinternet as most of the time data files aretransferred from one system to another . Melissa,Bloodhound , etc .are the examples of macro virus

.


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STEALTH VIRUSThese types of viruses have the capability to

change their appearance by changing theircodes . This way , they can hide theirexistence from the virus scanner programs .

Sometimes , it hides the increased size of filedue to virus infection causing the file to bescanned as an infected file . Frodo , Brain are

the examples of stealth virus .


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HOW THE VIRUS SPREAD ?Viruses programs are created in such a way that

they can easily replicate itself once entered in thecomputer system as soon as an infected program isexecuted , the virus code is executed first and startscreating its copies to the other programs or bootrecords . Sometimes they stay inside the memoryof computer till it is switched off and sometimes itstays active till the infected application running .

They spread through storage media , networks andinternet . When the system is switched off , thevirus vanishes the memory but resides in the

infected area .


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Effects Of Virus ON Your SystemThe available memory of the system decreased

drastically .The working speed of the system gets slower .

Unusual messages or characters started

appearing on the screen .Data file damaged or corrupted showing unusual

characters or symbols in place of actual data .

Sometimes even the whole hard disc getreformatted .


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Preventive Measures

From VirusIt is rightly said that Prevention is

better than cure . So , it is alwaysbetter to take the preventive measures

to safeguard your system from any

type of virus attack .


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PREVENTIVE MEASURESAvoid the use of external or unknown discs

and if required , scan the disc properly withsome good antivirus software .

While working with your e-mail account ,

do not open the unknown mails .Before downloading any file or program

from the internet make it sure that thesource that you are using is reliable one.

Never install the pirated software in your

system .


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Install an effective Antivirus software in

your system and update it periodically .

If your system is connected on a local areanetwork , then restrict the access to your

computer and allow only the genuine users to

use the system resource .Always keep a backup copy of your data files .


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ANTIVIRUS SOFTWAREAnti Virus software are the utilities which prevent

the viruses to enter in your system . They can alsodetect and remove the virus entered in your system .These are the memory resident programs andactivated as soon as the system is started . It checksall the files in the system and in case any virus isdetected , it removes the virus . It is very importantto keep your Anti Virus software updated with the

definitions of new viruses . Some popular Anti Virussoftware are :

Norton Anti Virus from Symantec

McAfee


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SPYWAREThese are the kind of software , downloaded

on your computer without your knowledge totrack your activities and to report the sameto the people who are ready to pay for it .

They can also be used to collect personalinformation of someone for the purpose ofidentity theft or fraud .Normally they collect

the information like : e-mail address ,passwords , credit card umbers , web pagesvisited , etc .


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SPAMSSpam are the unwanted messages which

are forcefully sent to a large number ofpeople who otherwise do not want toreceive these messages . The most commoform of spam is unwanted electronic junk

mails in which a single message is sentto individual users with direct addresses. In these mails services and products are

promoted by various companies . Most ofthe time these are annoying butharmless . However , sometimes these areused for identify theft or another fraud .

ADWARE


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ADWAREThese are the programs , which deliver

unwanted aids in he form of pop-ups toyour computer . While browsing theinternet these pop-ups start downloading

by themselves to your computer and thisway they eats up the band width of yourinternet connection . Due to the non-availability of sufficient band width thebrowsing becomes slower and yourrequired pages take more time to appearin the web browser .

PHISHING


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PHISHINGIt is one of the fraudulent process to acquiresome secret information from the user likecredit card number , net banking passwords ,account data , etc . with the help of anauthentic looking e-mail or website . For

example , you may receive an e-mail fromyour bank asking you to update yourinformation regarding your user ID andpassword of your net banking account . The

mail which appears to be genuine one sentby the bank collects the sensitive informationand sends it to fraudulent people who may

use it later for some cyber crime .


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HACKERS

A Hacker is a person who possesses high level of

computer skills and having good knowledge of the

machine and operating system . He attempts to

gain access on a remote computer for which heis not authorized for the purpose of corrupting or

stealing data in that system . But the main aimof the hacking is to know the details of the

system and how do they work . CRACKERS


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CRACKERSA Cracker is a person who is expert in

breaking the security of a system ornetwork to steal important informationwithout the concept of the other

person . Because of this , they are alsoknown as cyber burglars . As theirintention is always to cause damage o

the other users they are considered tobe more dangerous them the hackers .


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FIREWALLSThese can be the hardware or softwarewhich protects a system , network orserver from the virus or hackers attack .

It acts like a traffic cop , allowing ordisallowing access to a computer ornetwork or based on the predefined

rules .

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system security ppt.pptx