This chapter discusses computer security and various security mechanisms. It defines computer security as techniques to protect computers from accidental or intentional harm. The security goals of data confidentiality, data integrity, and system availability are explained. Common computer threats include physical damage, malicious programs like viruses and worms, and intruders. Security mechanisms to help prevent threats include regularly backing up data, using antivirus software, firewalls, strong passwords and authentication, and encryption.
This document discusses computer security risks and safeguards. It describes various types of cybercriminals like hackers, crackers, and corporate spies. It also outlines different internet and network attacks such as viruses, worms, Trojan horses, and denial of service attacks. Finally, it provides tips to prevent unauthorized access through techniques like installing antivirus software, updating definitions, and inoculating program files. The overall document aims to define computer security risks and describe methods to protect against internet attacks, unauthorized access, and information theft.
1. The document discusses cyber security issues related to business networks, the internet, and future trends. It covers topics like viruses, hackers, identity theft, spyware, firewalls, passwords, and disaster recovery.
2. Mechanisms for protecting against cyber threats are examined, including keeping software updated, using antivirus software, installing spyware protection, implementing firewalls, and creating strong passwords.
3. Looking ahead, the future of cyber security will be shaped by emerging technologies, more internet-connected devices, increased amounts of personal data online, and growth in cloud computing services. Security challenges will rise as younger users and billions more devices come online.
Online access and computer security.pptx_S.GauthamJoelGautham
This document discusses various computer security threats such as viruses, worms, Trojans, spyware, adware, spamming, and phishing. It describes how these threats can damage computers or steal personal information. It then provides recommendations for both active protection methods like antivirus software and preventative measures like strong passwords and caution when online. Firewalls, both software and hardware, are also presented as tools to enhance computer security.
Computer , Internet and physical security.Ankur Kumar
It refers to protection of a computer and the information stored in it, from the unauthorised users.
Computer security is a branch of computer technology known as information security as applied to computers and networks.
Computer security risks include cybercrime, hackers, crackers, script kiddies, cyberextortionists, and cyberterrorists illegally accessing networks and computers. To protect against viruses and malware, precautions should be taken like not opening attachments from unknown sources, enabling macro security in programs, installing antivirus software and updating it frequently with the latest virus definitions.
This document provides information on maintaining computer security, including summarizing basic computer maintenance tasks like disk cleanup and defragmentation. It also outlines common computer security threats like viruses, spyware, and phishing, and explains how to protect against them using antivirus software, firewalls, and other security best practices. The document gives instructions on encrypting files, activating Windows firewall, and provides troubleshooting tips for issues like computer freezing or hardware failures. Overall it serves as an introduction to maintaining computer security, protecting files and resolving common problems.
Antivirus software scans for, detects, and removes malicious software like viruses, worms, trojans, and adware. It runs continuously in the background to protect the computer. While antivirus software effectively prevents malware damage, it can slow computers and not catch every virus. It is important to keep antivirus software updated to recognize new viruses and protect systems.
This document discusses various computer security risks and precautions users can take. It defines different types of threats like hackers, crackers, and cybercriminals. It also explains different attacks like cyberterrorism and how viruses can spread. The document recommends precautions like not opening unexpected email attachments, using antivirus software, and updating signatures regularly to help safeguard against malware infections.
This document discusses computer security risks and safeguards. It describes various types of cybercriminals like hackers, crackers, and corporate spies. It also outlines different internet and network attacks such as viruses, worms, Trojan horses, and denial of service attacks. Finally, it provides tips to prevent unauthorized access through techniques like installing antivirus software, updating definitions, and inoculating program files. The overall document aims to define computer security risks and describe methods to protect against internet attacks, unauthorized access, and information theft.
1. The document discusses cyber security issues related to business networks, the internet, and future trends. It covers topics like viruses, hackers, identity theft, spyware, firewalls, passwords, and disaster recovery.
2. Mechanisms for protecting against cyber threats are examined, including keeping software updated, using antivirus software, installing spyware protection, implementing firewalls, and creating strong passwords.
3. Looking ahead, the future of cyber security will be shaped by emerging technologies, more internet-connected devices, increased amounts of personal data online, and growth in cloud computing services. Security challenges will rise as younger users and billions more devices come online.
Online access and computer security.pptx_S.GauthamJoelGautham
This document discusses various computer security threats such as viruses, worms, Trojans, spyware, adware, spamming, and phishing. It describes how these threats can damage computers or steal personal information. It then provides recommendations for both active protection methods like antivirus software and preventative measures like strong passwords and caution when online. Firewalls, both software and hardware, are also presented as tools to enhance computer security.
Computer , Internet and physical security.Ankur Kumar
It refers to protection of a computer and the information stored in it, from the unauthorised users.
Computer security is a branch of computer technology known as information security as applied to computers and networks.
Computer security risks include cybercrime, hackers, crackers, script kiddies, cyberextortionists, and cyberterrorists illegally accessing networks and computers. To protect against viruses and malware, precautions should be taken like not opening attachments from unknown sources, enabling macro security in programs, installing antivirus software and updating it frequently with the latest virus definitions.
This document provides information on maintaining computer security, including summarizing basic computer maintenance tasks like disk cleanup and defragmentation. It also outlines common computer security threats like viruses, spyware, and phishing, and explains how to protect against them using antivirus software, firewalls, and other security best practices. The document gives instructions on encrypting files, activating Windows firewall, and provides troubleshooting tips for issues like computer freezing or hardware failures. Overall it serves as an introduction to maintaining computer security, protecting files and resolving common problems.
Antivirus software scans for, detects, and removes malicious software like viruses, worms, trojans, and adware. It runs continuously in the background to protect the computer. While antivirus software effectively prevents malware damage, it can slow computers and not catch every virus. It is important to keep antivirus software updated to recognize new viruses and protect systems.
This document discusses various computer security risks and precautions users can take. It defines different types of threats like hackers, crackers, and cybercriminals. It also explains different attacks like cyberterrorism and how viruses can spread. The document recommends precautions like not opening unexpected email attachments, using antivirus software, and updating signatures regularly to help safeguard against malware infections.
The document discusses computer security and threats. It defines computer security as protecting computer systems and information from unwanted access, damage, or modification. It describes three types of computer security: hardware security, software/data security, and network security. It also discusses various threats like viruses, Trojans, hackers, and natural disasters. It provides checklists and security measures like backups, antivirus software, firewalls, and access controls to protect against these threats.
we have made this like computer application course material which is so functionable and any one can use it to develop your technological concept skill.
We Belete And Tadelech
This document provides information about computer security, including definitions, types of security threats, and security measures. It discusses hardware, software, data, and network security. Security threats include viruses, Trojan horses, worms, hackers, and natural disasters. Security measures to address these threats include data backups, cryptography, antivirus software, anti-spyware software, firewalls, and ensuring proper human security procedures are followed. The relationship between security threats and measures is that threats can come in various forms, while security measures are implemented to prevent unauthorized access or damage from these threats.
Network security involves protecting computer networks from unauthorized access and system damage. It ensures only authorized users can access network resources and data through authentication methods like usernames and passwords. Network security is needed because increased Internet usage has led to more hackers and attacks, putting networking systems and stored data at risk of viruses, delays, modifications or identity theft. Various security measures can help, such as antivirus software to detect malware, data loss prevention to restrict data sharing, email security to filter viruses and information leaks, and mobile security like antivirus to safeguard devices.
This document provides an overview of information security and privacy topics including computer viruses, how they work and spread, common types of viruses, virus prevention, and data security issues in the United States. It defines computer viruses, explains how they are able to replicate and attach to other programs, and notes they are created by people rather than naturally occurring. Popular virus types like file infectors, boot sector viruses, Trojan horses, and worms are described. The document also covers virus symptoms, prevention methods like antivirus software and firewalls, computer crime categories, and the 1974 Privacy Act.
This document discusses information security and privacy. It begins by defining computer viruses and how they work, reproducing and attaching to other programs. It then discusses popular types of viruses like file infectors, boot sector viruses, Trojan horses, and worms. The document outlines how viruses can damage systems and be spread, as well as common symptoms. It recommends prevention methods like antivirus software and firewalls. The document concludes by covering data security issues in the US, categories of security breaches, and the Privacy Act of 1974.
This document provides information about computer viruses and anti-virus software. It begins with an introduction to viruses, their history, symptoms and types. It then discusses various anti-virus programs like Norton, McAfee, Sophos, Kaspersky, Bit Defender and Avast. It explains the working of anti-virus software through signature detection and generic scanning. It notes the types of anti-viruses as those for personal and enterprise use and the actions they can take to detect and remove viruses.
The document discusses operating systems and computer security. It defines an operating system as software that tells hardware what to do and acts as an interface between applications and hardware. It then discusses types of operating systems like Windows and Linux. It also discusses security threats to computers like viruses and unauthorized access. It recommends measures like passwords, backups, and antivirus software to improve security.
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This document provides lecture notes on information security. It covers four modules: (1) the security problem in computing and elementary cryptography; (2) program security, operating system protection, and trusted OS design; (3) database security and security in networks; (4) administering security, legal and ethical issues. Key topics include computer threats like viruses and malware, network attacks like denial of service, and security controls like encryption, firewalls, and intrusion detection systems. The goal is to educate students on fundamental concepts of information security.
Lecture 8 privacy, security, ergonomics and the environment Jenny Coloma
The document discusses several topics related to computer use and security, including privacy issues, computer crimes, security measures, ergonomics, and health concerns. Specifically, it defines privacy and discusses issues around large databases and private networks. It also defines computer security and different types of computer crimes. The document outlines some security measures like passwords, antivirus software, firewalls, and backups. It defines ergonomics and its importance in reducing fatigue. Finally, it discusses the importance of considering mental and physical health for computer users.
This document discusses basic concepts in computer security. It defines computer security as techniques for ensuring data cannot be read or compromised without authorization, usually through encryption and passwords. The three main goals of computer security are confidentiality, integrity, and availability. Vulnerabilities are weaknesses that can be exploited, and threats are circumstances with potential to cause harm. Common threats include interception, interruption, modification, and fabrication. Controls are protective measures used to reduce vulnerabilities, and physical security and security methods like antivirus software and firewalls can help secure computers.
This document defines and explains essential security terminologies. It discusses key concepts like assets, access, attacks, controls, exploits, risks, threats, vulnerabilities, and more. It also covers specific types of malware and attacks, such as adware, denial-of-service attacks, botnets, encryption, firewalls, viruses, worms, spyware, ransomware, spam, zero-day vulnerabilities, phishing and others. The document is intended to provide an overview of common security terms and their meanings.
Implications of Computer Misuse and Cyber Security (Teaching) (1).pdfsrtwgwfwwgw
The document discusses the implications of computer misuse and cybersecurity. It begins with an introduction from the presentation group and defines key terms like computer misuse, cybersecurity, vulnerabilities, threats, attacks, and countermeasures. It then covers various types of threats like malware, password attacks, DDoS attacks, and vulnerabilities from both internal and external sources. Specific examples of countermeasures and how to prevent cyber attacks are provided. The document concludes by discussing the impact of computer misuse related to cyberbullying and ways to mitigate cyberbullying.
The document discusses computer security threats and solutions. It describes threats such as viruses, worms, trojans, spyware, adware, spamming, and hacking. Viruses can damage or delete files, slow down the computer, and invade email. Spyware tracks user activities while adware delivers unwanted pop-ups. Spamming sends bulk emails that clog servers. Hacking enables intruders to delete data or deny access. Solutions include using antivirus software, updating systems, caution when downloading, and firewalls to protect against threats actively and through prevention.
This document discusses computer security threats and solutions. It describes how computers can become insecure if data is not trustworthy or behaves unexpectedly. Common threats include viruses, worms, Trojan horses, spyware, adware, spamming, and PC intrusion. Viruses can damage or delete files, slow computers down, and invade email programs. Spyware and adware track user activities and display unwanted pop-up ads. Spamming disrupts email delivery through bulk messages. Hackers also try to intrude PCs. The document recommends both active protection methods like antivirus software and preventative measures like updating systems and using caution online to secure computers against these threats.
This lecture includes introduction to computers security and privacy. This lecture include basic concepts of terminologies and technologies involve in current securities and privacy needs.
This document discusses various ethical and security issues related to information technology. It raises questions about privacy and monitoring user activity online. It also covers different types of security threats like viruses, hacking, and spam emails. Various security measures are described such as encryption, access control, password policies, antivirus software, firewalls, and auditing user activity. Cyber crimes in India have been increasing and the document outlines some key cyber security statistics. Overall it provides an overview of important ethical and security concerns for information technology.
Security & control in management information systemOnline
The document discusses security concepts in information systems including prevention of unauthorized access, modification, and deletion of information. It outlines unintentional threats like human error and intentional threats like criminal attacks. The goals of information security are prevention, detection, and response. Risks to applications and data include computer crime, hacking, cyber-theft, unauthorized work use, software piracy, and viruses/worms. Risks to hardware include natural disasters, blackouts, and vandalism. Major defense strategies are encryption, authentication, firewalls, email monitoring, antivirus software, backup files, security monitors, and biometric controls. The document also discusses disaster recovery, business recovery plans, and general controls to minimize errors and disasters.
Honeypots Unveiled: Proactive Defense Tactics for Cyber Security, Phoenix Sum...APNIC
Adli Wahid, Senior Internet Security Specialist at APNIC, delivered a presentation titled 'Honeypots Unveiled: Proactive Defense Tactics for Cyber Security' at the Phoenix Summit held in Dhaka, Bangladesh from 23 to 24 May 2024.
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Similar to Computer Security update and virus .pptx
The document discusses computer security and threats. It defines computer security as protecting computer systems and information from unwanted access, damage, or modification. It describes three types of computer security: hardware security, software/data security, and network security. It also discusses various threats like viruses, Trojans, hackers, and natural disasters. It provides checklists and security measures like backups, antivirus software, firewalls, and access controls to protect against these threats.
we have made this like computer application course material which is so functionable and any one can use it to develop your technological concept skill.
We Belete And Tadelech
This document provides information about computer security, including definitions, types of security threats, and security measures. It discusses hardware, software, data, and network security. Security threats include viruses, Trojan horses, worms, hackers, and natural disasters. Security measures to address these threats include data backups, cryptography, antivirus software, anti-spyware software, firewalls, and ensuring proper human security procedures are followed. The relationship between security threats and measures is that threats can come in various forms, while security measures are implemented to prevent unauthorized access or damage from these threats.
Network security involves protecting computer networks from unauthorized access and system damage. It ensures only authorized users can access network resources and data through authentication methods like usernames and passwords. Network security is needed because increased Internet usage has led to more hackers and attacks, putting networking systems and stored data at risk of viruses, delays, modifications or identity theft. Various security measures can help, such as antivirus software to detect malware, data loss prevention to restrict data sharing, email security to filter viruses and information leaks, and mobile security like antivirus to safeguard devices.
This document provides an overview of information security and privacy topics including computer viruses, how they work and spread, common types of viruses, virus prevention, and data security issues in the United States. It defines computer viruses, explains how they are able to replicate and attach to other programs, and notes they are created by people rather than naturally occurring. Popular virus types like file infectors, boot sector viruses, Trojan horses, and worms are described. The document also covers virus symptoms, prevention methods like antivirus software and firewalls, computer crime categories, and the 1974 Privacy Act.
This document discusses information security and privacy. It begins by defining computer viruses and how they work, reproducing and attaching to other programs. It then discusses popular types of viruses like file infectors, boot sector viruses, Trojan horses, and worms. The document outlines how viruses can damage systems and be spread, as well as common symptoms. It recommends prevention methods like antivirus software and firewalls. The document concludes by covering data security issues in the US, categories of security breaches, and the Privacy Act of 1974.
This document provides information about computer viruses and anti-virus software. It begins with an introduction to viruses, their history, symptoms and types. It then discusses various anti-virus programs like Norton, McAfee, Sophos, Kaspersky, Bit Defender and Avast. It explains the working of anti-virus software through signature detection and generic scanning. It notes the types of anti-viruses as those for personal and enterprise use and the actions they can take to detect and remove viruses.
The document discusses operating systems and computer security. It defines an operating system as software that tells hardware what to do and acts as an interface between applications and hardware. It then discusses types of operating systems like Windows and Linux. It also discusses security threats to computers like viruses and unauthorized access. It recommends measures like passwords, backups, and antivirus software to improve security.
FellowBuddy.com is an innovative platform that brings students together to share notes, exam papers, study guides, project reports and presentation for upcoming exams.
We connect Students who have an understanding of course material with Students who need help.
Benefits:-
# Students can catch up on notes they missed because of an absence.
# Underachievers can find peer developed notes that break down lecture and study material in a way that they can understand
# Students can earn better grades, save time and study effectively
Our Vision & Mission – Simplifying Students Life
Our Belief – “The great breakthrough in your life comes when you realize it, that you can learn anything you need to learn; to accomplish any goal that you have set for yourself. This means there are no limits on what you can be, have or do.”
Like Us - https://www.facebook.com/FellowBuddycom
This document provides lecture notes on information security. It covers four modules: (1) the security problem in computing and elementary cryptography; (2) program security, operating system protection, and trusted OS design; (3) database security and security in networks; (4) administering security, legal and ethical issues. Key topics include computer threats like viruses and malware, network attacks like denial of service, and security controls like encryption, firewalls, and intrusion detection systems. The goal is to educate students on fundamental concepts of information security.
Lecture 8 privacy, security, ergonomics and the environment Jenny Coloma
The document discusses several topics related to computer use and security, including privacy issues, computer crimes, security measures, ergonomics, and health concerns. Specifically, it defines privacy and discusses issues around large databases and private networks. It also defines computer security and different types of computer crimes. The document outlines some security measures like passwords, antivirus software, firewalls, and backups. It defines ergonomics and its importance in reducing fatigue. Finally, it discusses the importance of considering mental and physical health for computer users.
This document discusses basic concepts in computer security. It defines computer security as techniques for ensuring data cannot be read or compromised without authorization, usually through encryption and passwords. The three main goals of computer security are confidentiality, integrity, and availability. Vulnerabilities are weaknesses that can be exploited, and threats are circumstances with potential to cause harm. Common threats include interception, interruption, modification, and fabrication. Controls are protective measures used to reduce vulnerabilities, and physical security and security methods like antivirus software and firewalls can help secure computers.
This document defines and explains essential security terminologies. It discusses key concepts like assets, access, attacks, controls, exploits, risks, threats, vulnerabilities, and more. It also covers specific types of malware and attacks, such as adware, denial-of-service attacks, botnets, encryption, firewalls, viruses, worms, spyware, ransomware, spam, zero-day vulnerabilities, phishing and others. The document is intended to provide an overview of common security terms and their meanings.
Implications of Computer Misuse and Cyber Security (Teaching) (1).pdfsrtwgwfwwgw
The document discusses the implications of computer misuse and cybersecurity. It begins with an introduction from the presentation group and defines key terms like computer misuse, cybersecurity, vulnerabilities, threats, attacks, and countermeasures. It then covers various types of threats like malware, password attacks, DDoS attacks, and vulnerabilities from both internal and external sources. Specific examples of countermeasures and how to prevent cyber attacks are provided. The document concludes by discussing the impact of computer misuse related to cyberbullying and ways to mitigate cyberbullying.
The document discusses computer security threats and solutions. It describes threats such as viruses, worms, trojans, spyware, adware, spamming, and hacking. Viruses can damage or delete files, slow down the computer, and invade email. Spyware tracks user activities while adware delivers unwanted pop-ups. Spamming sends bulk emails that clog servers. Hacking enables intruders to delete data or deny access. Solutions include using antivirus software, updating systems, caution when downloading, and firewalls to protect against threats actively and through prevention.
This document discusses computer security threats and solutions. It describes how computers can become insecure if data is not trustworthy or behaves unexpectedly. Common threats include viruses, worms, Trojan horses, spyware, adware, spamming, and PC intrusion. Viruses can damage or delete files, slow computers down, and invade email programs. Spyware and adware track user activities and display unwanted pop-up ads. Spamming disrupts email delivery through bulk messages. Hackers also try to intrude PCs. The document recommends both active protection methods like antivirus software and preventative measures like updating systems and using caution online to secure computers against these threats.
This lecture includes introduction to computers security and privacy. This lecture include basic concepts of terminologies and technologies involve in current securities and privacy needs.
This document discusses various ethical and security issues related to information technology. It raises questions about privacy and monitoring user activity online. It also covers different types of security threats like viruses, hacking, and spam emails. Various security measures are described such as encryption, access control, password policies, antivirus software, firewalls, and auditing user activity. Cyber crimes in India have been increasing and the document outlines some key cyber security statistics. Overall it provides an overview of important ethical and security concerns for information technology.
Security & control in management information systemOnline
The document discusses security concepts in information systems including prevention of unauthorized access, modification, and deletion of information. It outlines unintentional threats like human error and intentional threats like criminal attacks. The goals of information security are prevention, detection, and response. Risks to applications and data include computer crime, hacking, cyber-theft, unauthorized work use, software piracy, and viruses/worms. Risks to hardware include natural disasters, blackouts, and vandalism. Major defense strategies are encryption, authentication, firewalls, email monitoring, antivirus software, backup files, security monitors, and biometric controls. The document also discusses disaster recovery, business recovery plans, and general controls to minimize errors and disasters.
Honeypots Unveiled: Proactive Defense Tactics for Cyber Security, Phoenix Sum...APNIC
Adli Wahid, Senior Internet Security Specialist at APNIC, delivered a presentation titled 'Honeypots Unveiled: Proactive Defense Tactics for Cyber Security' at the Phoenix Summit held in Dhaka, Bangladesh from 23 to 24 May 2024.
HijackLoader Evolution: Interactive Process HollowingDonato Onofri
CrowdStrike researchers have identified a HijackLoader (aka IDAT Loader) sample that employs sophisticated evasion techniques to enhance the complexity of the threat. HijackLoader, an increasingly popular tool among adversaries for deploying additional payloads and tooling, continues to evolve as its developers experiment and enhance its capabilities.
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2. CS101 Introduction to Computer Science
Introduction
• Since prevention is always more than cure,
• but if infection occurred in some way we will also
see some security mechanisms to help prevent th
e situation.
• All security mechanisms don’t solve all types of
computer security dangers.
3. CS101 Introduction to Computer Science
What is computer security?
• Computer security refers to the set of techniques develo
ped to help protect single and network linked computer
s from accidental or intentional harm.
• A computer system can be damaged due to accidental o
r intentional hardware and software mismanagement.
• Computer security also involves issues pertaining to hu
man error, loss of training and criminal activities like
creating computer viruses and an attempt to access conf
idential information by unauthorized individuals.
4. CS101 Introduction to Computer Science
Security Goals
• Data Confidentiality
It is concerned with having secret data remain secret
• Data Integrity
Unauthorized users should not be able to modify any data without t
he owners permission
Includes removing data and adding false data
• System Availability
Means nobody can disturb the system to make it unusa
ble
5. CS101 Introduction to Computer Science
General computer threats
• Computer hazards range from the destruction of
the computer hardware and hence loss of data d
ue to natural disaster to the modification and th
eft of confidential information on the computer.
• Currently computer security has become a very s
erious issue in the Information and communicatio
n technology realm.
• All your files of years of work can be lost forever
in a fraction of seconds after infection by a malic
ious computer virus.
6. CS101 Introduction to Computer Science
General computer threats
• There are numerous cases where very big organizations and busin
esses have lost their thousands of customers’ data.
• The types of computer security danger are also escalating. Since
computers have become global in this era,
• the threat concerns every field. In today’s world where busy air traf
fic and nuclear weapons are controlled by computers a failure on c
omputer system means an utter disaster.
7. CS101 Introduction to Computer Science
• Generally, hazards to the computers can be catego
rized into three major categories.
Physical hazards
Malicious programs
Intruder
8. CS101 Introduction to Computer Science
Physical Threat
• Damages to the computer’s hardware can be caused due
to the number of reasons; among which fire and flood be
ing the most prominent ones.
• There are lots of cases where accidents and natural disa
sters have destroyed years of accumulated data. Besides
to such kinds of catastrophic events, computer’s hardwar
e can also be damaged due to excessive heat, dust and
moisture.
9. CS101 Introduction to Computer Science
Malicious programs
• There are lots of malicious programs written to disrupt
the computer system. Among which the most important
ones are the following:
Computer Virus
Worm
Trojan Horse
10. CS101 Introduction to Computer Science
Computer virus
• Computer viruses operate, replicate and cause damage only when t
hey are run.
• That means, if an infected computer file is exist in on the computer’s
hard disc, or is simply attached to an infected computer network or d
ownloading an infected program, it will not necessarily become infec
ted.
• Computer viruses activate when the instructions or executable code
that run programs are opened.
• When an infected file or program is opened, the virus’ code will also
be opened on RAM.
• Then the processor follows the virus’ instruction that orders it to repl
icate, infect other files and cause any damage.
• Once a virus is active, it may replicate by various means and tries to
infect the computer’s files or the operating system
11. CS101 Introduction to Computer Science
Types of virus
I. Parasitic or file viruses infect executable files or programs that a
re identified by the extension .exe.
II. Bootstrap-sector viruses exist in on the first portion of the hard
disk or floppy disk, known as the boot sector.
• These viruses replace either the programs that store information
about the disk's contents or the programs that start the computer.
Typically, these viruses spread by means of the physical exchang
e of floppy disks.
I. Multi-partite viruses combine the abilities of the parasitic and the
bootstrap-sector viruses, and so are able to infect either files or
boot sectors.
• These types of viruses can spread if a computer user boots from an
infected diskette or accesses infected files.
12. CS101 Introduction to Computer Science
Worm
• Worm is a malicious program similar to a virus but is a s
elf-contained program that transports itself from one c
omputer to another through networks.
• Unlike a virus, worms don’t need to attach themselves to
an existing program.
• While viruses corrupt or modify files on a computer, wo
rms copy themselves exceedingly and cause the computer
to be extremely slow.
• Worms also cause harm to the network by consuming its
bandwidth.
13. CS101 Introduction to Computer Science
Trojan horse
• Trojan horse is a program that pretends to be something
interesting and harmless, such as a game , PDF , Softwa
re… but when it runs it may have harmful effects.
• Unlike virus or worms, Trojan horse programs don’t repli
cate themselves. Instead, they might lie dormant for mo
nths before they are activated and do something devious t
o the computer
14. CS101 Introduction to Computer Science
Security mechanisms
• There are various ways that we can use to help protect our compute
r’s hardware, software and data from numerous possible threats.
• Since prevention is better and easier to deal with than trying to cure
after infection, most of the security mechanisms that would be discus
sed here deals with prevention.
• All security mechanisms don’t solve all the security threats.
• the followings are security mechanisms
Back up
Antivirus software
Fire wall
Use of password and authentication methods
Encryption
15. CS101 Introduction to Computer Science
Backup
• the most important security mechanism of all since computer syst
ems can fail in number of ways and the only way that we can restor
e the loss is from what we have stored as back up.
• Storing backup copies of software and data and having backup co
mputer and communication capabilities are important basic safegu
ards because the data can then be restored if it was altered or destroy
ed by a computer crime or accident.
• Computer data should be backed up frequently and should be store
d nearby. in secure locations in case of damage at the main site.
• Transporting sensitive data to storage locations should also be done s
ecurely
16. CS101 Introduction to Computer Science
Antivirus software
• is computer programs that attempt to identify, neutralize or elimin
ate malicious software.
• Antivirus is so named because the earliest examples were designed e
xclusively to combat computer viruses
• most modern antivirus software is now designed to combat a wide ra
nge of threats including worms, Trojan horses, other malwares and
password theft attempts like Phishing.
• The installation of well-designed and recent antiviral software can he
lp prevent a viral infection and thereby help stop its spread. Since n
ew viruses and other threats are appearing each day the antiviral soft
ware need also be updated regularly. The update mostly contains the
characteristics of the new viruses and threats.
17. CS101 Introduction to Computer Science
Fire wall
•is a device or a software that blocks unauthorized access to the single
or network linked computers based on a set of rules and other criteria.
•The firewall acts much like a guard when it looks at network traffic d
estined for or received from another computer.
•The firewall determines if that traffic should continue on to its destin
ation or be stopped.
•A firewall acts as the local area networks gateway to the Internet or it
can be a dedicated computer placed between the local area network a
nd the Internet, so that the network is never in direct contact with the In
ternet.
•The firewall also keeps track of every file entering or leaving the local
area network in order to detect the sources of viruses and other problem
s that might enter the network.
18. CS101 Introduction to Computer Science
Use of password and authentication methods
• Another technique to help prevent abuse and misuse of computer data i
s to limit the use of computers and data files to approved persons.
• Security software can verify the identity of computer users and limit
their privileges to use, view, and alter files.
• The software also securely records their actions to establish accountab
ility.
• It is also possible to give different levels of access to the same type of
data where some users can only be able to see the document while other
s have the right to modify.
• passwords must be difficult to guess and should not be found in dictio
naries.
• Effective passwords contain a variety of characters and symbols that
are not part of the alphabet
19. CS101 Introduction to Computer Science
Encryption
• Another technique to protect confidential information is encryption.
• Computer users can scramble information to prevent unauthorized us
ers from accessing it.
• Authorized users can unscramble the information when needed by usi
ng a secret code called a key.
• Without the key the scrambled information would be impossible or v
ery difficult to unscramble.
• Internet communication has lots of loop holes and we can’t be sure if
what we have sent for someone is accessed by another, whom we didn’t
address the message for