computer virus-and-antivirus

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Computer security Against threats

A presentation by Vishwaraj Yadav and Saurav Mohapatra of class 11th

Cannas

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Contents• Security of computer

• Threats to computer security

• Solutions to computer threats

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Security of system• Nowadays, Computers are used

everywhere. Various data is shared from one computer to another. But sometimes the data is not trustworthy, or it behaves in an undesired manner. If this happens then our computer is insecure.

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• So to make our computer secured we need Computer security.

• It is the ability of computer to protect information & system resources with respect to confidentiality & integrity.

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• A threat is a potential violation to security. When it is executed it becomes attack.

Threats to computer security

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Threats to computer security

PC Intrusion

Spyware Adware Spamming Viruses

Worms

Trojans

Phishing

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Computer Virus• Viruses are malicious codes that cause

damage to data, they can attack to any part of computer’s software such as boot block, files & application programs etc.

• Worms & Trojan horses are similar programs having virus-like effects.

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Computer Virus

• Worms- A self-replicating program which eats up the entire disk space or memory.

• Trojan Horses- It is a program which appears harmless but performs malicious functions such as deleting or damaging files.

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Computer Virus

• How do viruses damage computer?

1. They damage or delete files.

2. Slow down the computer.

3. Invade your email program.

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Computer Viruses

Boot sector viruses

File viruses

Macro viruses

Multipartite viruses

Polymorphic viruses

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Computer Virus

Types of Computer Virus • Boot Sector Virus

Boot sector viruses infect the boot sectors on floppy disks and hard disks, and can also infect the master boot record on a user's hard drive.

• File Virus

Operate in memory and usually infect executable files.

• Polymorphic virus

They mutate their own code to make it difficult for antivirus to detect and remove.

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Computer Virus• Multi-partite Virus

Multi-partite viruses have characteristics of both boot sector viruses and file infector viruses.

• Macro Virus

They infect macro utilities that accompany such applications as Microsoft Word, Excel and outlook.

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Example of computer virus

I LOVE YOU• VBS/LoveLetter is a VBScript worm. It

spreads through e-mail as a chain letter. • This worm sends itself to email addresses in

the Microsoft Outlook address book and also spreads to Internet chatrooms.

• This worm overwrites files on local and remote drives, including files with the extensions .html, .c,.bat,.mp3 etc.

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spyware

• Spyware is a software which is installed in the computer to spy on the activities done on the computer.

• It tracks what all user does and reports it to the central source. They are used to spy either for legal purpose or illegal purpose.

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Spyware

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spyware

• How do spyware cause damage?

1. They monitor information such as what sites you visit or record keystrokes which can lead to identity thefts.

2. Some spywares alter PC settings like position of your desktop icons etc.

3. It can rob the PC of system speed and internet access efficiency.

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Adware

• These are programs that deliver unwanted ads to computer(in the form of pop-ups).

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Adware

• How do adware damage computer?

1. Adware tracks the information just like spyware.

2. When adware infects the computer, we will receive frequent pop-ups appearing out of nowhere.

3. The appearing of large number of ads ,the PC starts to slow down.

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Spamming

• Spamming refers to sending of bulk-mail by an identified or unidentified source. The attacker keeps on sending bulk mail to various accounts until mail server runs out of disk space.

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Spamming

• How do spams damage computer?

1. Spam messages circulating across internet disrupt email delivery & system performance.

2. Spams eats up time.

3. Spam messages contain fraud material and can even spread viruses.

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PC Intrusion

• Every PC connected to Internet are target of hackers. Hackers constantly attack computers.

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PC Intrusion

• How can it damage the system?

1. Sweeper attack- Hackers use it to delete all the data in the system.

2. Denial of service- Thais attack eats up all the resources of system and system or application doesn’t work.

3. Password guessing- Hackers crack or guess passwords of account to gain entry into remote computer systems.

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Solutions to computer threats

• The computer security protects the computer through threats by taking actions or taking prevention. There are two solutions to these threats-

1. Active Protection

2. Preventive Maesures

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• Active Protection- Installing and using antivirus that includes Internet security-which includes protection against viruses, spyware & PC intrusion.

• Preventive measures- Even though security programs detect & eliminate threats but we should help prevent these issues from ever arising.

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• Solutions to viruses, adware,spyware

1. Active protection• Use Anti-virus and Anti-spyware

software.• Download updates regularly.• Run frequent full-system scans.

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2. Preventive measures• Keep your system up-to-date.• Use caution when downloading files on

the internet.• Be careful with email.• Disable Cookies, if possible.

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• Solutions to Spam

1. Active Protection:-Methods used by

anti-spam software-

(a)Sender FilteringDigital CertificatesDigital Signatures

(b)Keyword Filtering

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Solutions to PC intrusion:-AuthorizationAuthenticationFirewall

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Thank U 4

ur attention