online access and computer security class 11 notes


online access and computer security class 11 notes

online access and computer security class 11 notes

online access and computer security class 11 notes


What is computer security?

Computer security basically is the protection of computer systems and information from harm, theft, and unauthorized use. It is the process of preventing and detecting unauthorized use of your computer system.

There are various types of computer security which is widely used to protect the valuable information of an organization.


A threat is a potential violation of security. when a threat is actually executed, it becomes attack. Those who execute such actions,
or cause them to be executed are called attackers.

some common threats the average computer user faces every day:-

(1) viruses
(2) spyware
(3) adware
(5)PC intusion

computer viruses:-

computer viruses are malicious codes/programs that cause damage to data and files on a system.
Viruses can attack any part of a computer’s software such as boot block, operating system, system areas, files and application-program-macros etc.

(a) worms:-

A worm is self-replicating program which eats up the entire disk space or memory.
worms class 11 computer science

worms class 11 computer science


(b) Trojan horses:-

a Trojan horse is a program that appears harmless but actually performs malicious function such as deleting or damaging files.
Trojan horses class 11

Trojan horses


damage caused by viruses:-

viruses can do the following if left unchecked:-

(1) damage or delete files
(2)  slow down your computer
(3) invade your email program


Spyware is a software which is installed on your compute to spy on your activities and report this data to people willing to pay for it.
It track user’s behaviour and reports information back to a central source. These are used to spy on some one for legal or illegal purpose.
spyware class 11

spyware class 11


damage caused by spyware:-

(1) compromises your data, computing habits, and identity
(2)alters pc settings
(3) slows down your pc


These are the programs that deliver unwanted ads to your computer. They consume your network bandwidth .
Adware is similar to spyware-however, it may be installed with your consent.
So it is advised that you thoroughly read installation agreements before allow installation of a software.
Adware class 11

Adware class 11


damage caused by Adware:-

(1)Adware tracks information just like spyware
(2) displays array of annoying advertising
(3) slows down your pc


Spamming refers to sending of bulk-mail by an identified or unidentified  source. in non-malicious form, bulk-advertising mail is sent to many accounts.
e.g.- e-mail bombing
spamming class 11

spamming class 11

damage caused by spamming:-

(1) spam reduces productivity
(2) spam eats up your time
(3) spam can lead to worse things

PC intrusion:-

Every pc connected to the internet is potential target for hackers.
computers are under constant attack from cyber vandals.
Pc intrusion can occur in any of the following form.
(1)sweeper attack
(2)denial of services
(3)password guessing
(online access and computer security class 11 notes)


unauthorised monitoring of other people’s communications is called eavesdropping.


The phishing is a type of social engineering attack often used to steal user data, including login credentials and credit card number etc.
phishing class 11

phishing class 11

ways of phishing:-

vishing refers to phishing done over phone calls.
SMS phishing or smishing is one of the easiest type of phishing attacks. engine phishing.
4.whaling:-attempts against a high profits targets.


The pharming is an attack in which hacker attempts to redirect a website’s traffic to another, bogus website. through pharming attacks, the attacker points you to a malicious and illegitimate website by redirecting the legitimate URL.

pharming class 11

pharming class 11



Cookies are small files created on client computers when these systems browse certain web sites.
These cookies can contain information about the user.

These security and privacy concern are:-

(1)session data
(2)tracking information
(3)public computers

solutions to computer security threats:-

(1)active protection
(2)preventive measures
solutions to viruses, Adware and spyware
(1)use Anti-virus and Anti-spyware
(2)download update regularly
(3)run frequent full-system scan
(4)keep your system up-to-date
(5)use caution when downloading files on internet
(6)be careful with email
(7)disable cookies, if possible

solution to spam, Eavesdropping:-

(1)sender filtering
(2)digital certificates
(3)digital signatures
(4)keyword filtering
(5)keep your email address private

solutions to pc intrusion:-

(4)use proper file access permissions and sharing files on internet
(5)disconnect from the internet when away

solution to phishing pharming attack

(1)take the computer offline
(2)backup all files on the hard drive
(3)list the information given to phishing scammers
(4)run anti-virus software
(5)contact credit agencies to report any possibilities of identity theft
(6)don’t open emails from unknown sources

Prevention rate:

1. Do not open emails from unknown sources.
2. If in doubt, do not click.


A firewall is a network security system, either hardware or software-based, that controls incoming and outgoing network traffic based on a set of rulers

firewall can implemented in two forms:-

(1) software firewall
(2)hardware firewall

Internet Firewall is a custom tool or software

protect your computer from unwanted data and virus. A
the firewall is so named because of the actual glass used for protection
• Software Firewall: A software firewall is a special type of
computer software. It protects your computer from
external attempts to control or access.
• Hardware Firewall: It is a physical device is designed to perform firewall functions.

• The hardware fire extinguisher is actually possible
be another computer or a dedicated piece of service that is active
like a firefighter

Read More :


Computer Security video

video credit : Quick Support

Frequently Asked Questions

What is Computer Security explain?

Computer security, the protection of computer systems and information from harm, theft, and unauthorized use. Computer hardware is typically protected by the same means used to protect other valuable or sensitive equipment, namely, serial numbers, doors and locks, and alarms.

What is computer security and its types?

Network security is the practice of securing a computer network from intruders, whether targeted attackers or opportunistic malware. Application security focuses on keeping software and devices free of threats. A compromised application could provide access to the data its designed to protect.

What is computer security example?

For example, Information security is securing information from unauthorized access, modification & deletion. Computer Security means securing a standalone machine by keeping it updated and patched. Network Security is by securing both the software and hardware technologies.

What is computer security and why is it important?

Computer Security is important as it enables people to perform their work and study. It helps in the execution of essential business processes, and Safeguards confidential and sensitive information. Computer Security is important enough that it should be learned by everyone.

Why do we need computer security?

Computer security is the process of preventing and detecting unauthorized use of your computer. Prevention measures help you stop unauthorized users (hackers) from accessing any part of your computer system. … Often they want to gain control of your computer so they can use it to launch attacks on other computer systems.

What are the advantages of computer security?

the disadvantages and advantages of cyber security
1) Protects system against viruses, worms, spyware and other unwanted programs.
2) Protection against data from theft.
3) Protects the computer from being hacked.
4) Minimizes computer freezing and crashes.
5) Gives privacy to users.
1) Firewalls can be difficult to configure correctly.

What is computer security risk?

DEFINITION• Computer Security Risks is any event or action that could cause a loss of or damage to computer hardware, software, data, information, or processing capability.

What is computer safety and security?

Cyber safety is the safe and responsible use of information and communication technology. It includes body of technologies, processes and practices designed to protect networks, computers, programs and data from attack, damage or unauthorized access.

What are the basics of computer security?

Computer security can be defined as controls that are put in place to provide confidentiality, integrity, and availability for all components of computer systems. These components include data, software, hardware, and firmware.

What are the disadvantages of security?

Disadvantages of Security Guards
Modern live video surveillance systems offer many of the same advantages—without the large retainer or paycheck.
Security guards expose employers to greater liability and insurance costs. …
Security guards passively monitor property, and are prone to boredom-related failure.