Unit 3 Internet Basics

3.04 Malicious Software Can Travel and Spread3.04 Malicious Software Can Travel and Spread

Unit 3 Unit 3 Internet BasicsInternet Basics

Introduction• The objective of computer security includes

– protection of information and property from theft, corruption, or natural disaster,

• while allowing the information and property to remain accessible and productive to its intended users.

Introduction• At the end of this lesson, student will be able to:

– Practice safe, ethical, and legal use of technology systems and digital content. (ACOS #13)

– Explain consequences of unsafe and illegal use of technology systems and digital content (ACOS #13.B1)

– Distinguish between various forms of malicious code

Lesson: Computer Crime• In the early days of computing, a hacker was a person who enjoyed

learning details of computer systems and writing clever programs, referred to as hacks.

• Although many people still use the term hacker to describe software manipulation, it more commonly refers to unauthorized access to computer systems.

• In addition to programming his own computer, the hacker may break into others.

Lesson: Computer Crime• The most famous case of electronic trespassing was documented in Cliff

Stoll's best-selling book, The Cuckoo's Egg. • While working as a system administrator for a university computer lab in

1986, Stoll traced a 75-cent accounting error to a ring of hackers working for the KGB.

Lesson: Computer Crime• The most common form of computer crime, however, is theft. • Computers are used to steal money, goods, information, and computer

resources. • This may be accomplished through the use of malicious code, or malware,

which is software designed to infiltrate a computer system without the owner's consent.

• Malware includes but is not limited to the following:– adware, – computer viruses, – spyware, – Trojan horses, and – worms.

Lesson: Computer SecurityDefinitions

• Malware, (malicious) is software designed to infiltrate a computer system without the owner's consent . – Malware includes the following:

• Adware automatically plays, displays, or downloads advertisements to a computer after the software is installed on it

• Computer virus is a computer program that can copy itself and infect a computer. Viruses can increase their chances of spreading to other computers by infecting files on a network file system

• Spyware is a type of malware that is installed on computers and collects information about users without their knowledge

• Trojan Horse appears to perform a desirable function for the user but instead facilitates unauthorized access to the user's computer system

• Worm uses a network to send copies of itself to other nodes (computers on the network)


• Adware– Advertising is integrated into or bundled with the software

• Developer gets income from advertisers • Users may find ads to be

– Interruptions or annoyances – Distractions

• be given option to pay for a “licensed” copy to do away with the ads – Often appears in software that is free – Often designed to note what Internet sites the user visits – Adware can also download and install Spyware


• Computer Virus– Definition: a series of instructions buried into a program which cause

the computer to destroy data when given a certain signal – Virus is duplicated each time the software is copied

• It spreads • Can spread to all computers on a network


• Spyware– The presence of spyware is typically hidden from the user. – Spyware is known to change :

• computer settings, resulting in slow connection speeds • different home pages • and/or loss of Internet


• Trojan Horse– Designed to allow a hacker remote access to a target computer system – Possible for a hacker to access it remotely and perform various operations, such as:

• Data theft (e.g. passwords, credit card information, etc.) • Installation of software (including other malware) • Downloading or uploading of files • Modification or deletion of files • Keystroke logging • Viewing the user's screen • Wasting computer storage space

– Trojan horses require interaction with a hacker to fulfill their purpose– It is possible for hackers to scan computers on a network in the hope of finding one with a Trojan

horse installed, that the hacker can then use to control the target computer


• Worm– A computer worm is a self-replicating computer program – It uses a network to send copies of itself to other nodes (computers on the network) – This is due to the poor security the computers infected have – Unlike a virus, it does not need to attach itself to an existing program – Worms almost always cause at least some harm to the network, if only by consuming bandwidth,

whereas viruses almost always corrupt or modify files on a targeted computer – To prevent

• Be wary of opening unexpected email • Don’t run attached files or programs or visit web sites that are linked to such emails • Anti-virus and anti-spyware software are helpful, but must be kept up-to-date • The use of a firewall is also recommended.


• Phishing– Definition: The criminally fraudulent process of attempting to acquire sensitive

information such as usernames, passwords and credit card details by masquerading as a trustworthy site.

– The term is a variant of fishing; alludes to baits used to “catch” financial information and passwords

– Characteristics: • Lures unsuspecting public• Typically carried out by e-mail or instant messaging • Often directs users to enter details at a fake website that looks almost

identical to the legitimate one.


• Computer Crime– Willful destruction of computer data is vandalism – Electronic destruction

• More costly than physical destruction • May be life-threatening

– Computer crimes cost the nation billions of dollars each year

Lesson: Computer Security• Do you let spyware sneak onto your computer to give others a peek at

information you enter online? – Get wise to the spyware guise and test yourself by taking the On

Guard Online Spyware Quiz.• Take a screenshot at the end of the quiz

– Save to your F Drive in your Unit 3 Folder as» 3.04 On Guard Online Spyware Quiz

Lesson: Computer Security• A software virus works in the same way as a biological virus, which can

invade the cells of another organism and use the reproductive machinery of each host cell to make copies of itself.

• A software virus spreads from program to program, or from disk to disk, and uses each infected program or disk to make more copies of itself.

• Virus software is usually hidden in the operating system of a computer or in an application program.

• Some viruses do nothing but reproduce; others display messages on the computer's screen; still others destroy data or erase disks.


• Like viruses, worms (named for tapeworms), use computer hosts to reproduce themselves.

• But unlike viruses, worm programs travel independently over computer networks, seeking out uninfected workstations to occupy.

• A typical worm segment resides in a workstation's memory rather than on disk, so the worm can be eliminated by shutting down all of the workstations on the network.

Practice

• Open Microsoft Word and answer the 6 questions below– Save to your F Drive in your Unit 3 Folder as

• 3.04 Practice– Number 1. automatically plays, displays, or downloads advertisements to a computer

after the software is installed on it – Number 2. a computer program that can copy itself and infect a computer – Number 3. a type of malware that is installed on computers and collects information

about users without their knowledge – Number 4. appears to perform a desirable function for the user but instead facilitates

unauthorized access to the user's computer system – Number 5. uses a network to send copies of itself to other nodes (computers on the

network) – Number 6. Often directs users to enter details at a fake website that looks almost

identical to the legitimate one

Review• Willful destruction of computer systems and information is considered vandalism

and is a crime. • As a matter of fact, electronic destruction is more costly than physical destruction. • Of course, theft is theft whether it is robbing a bank or stealing money by gaining

access to a person’s account numbers through computer hacking. • Malicious software can certainly be aggravating to the user, but it can also destroy

your computer and data. • Criminals often use some form of malicious software to steal money from your

bank accounts and to steal your identity. • To protect yourself and your data, you should be aware of the potential threats.

Task

• Review the vocabulary words in this lesson – Complete the 3.04 Vocabulary Practice.

– The Quiz will ask you to match the vocabulary words to definitions and to select the appropriate word for a given sentence.

» You may use your notes and this PowerPoint to complete it.

Are you finished?• You should have 14 things saved on your F Drive in your Unit 3

Folder.1. 3.01 Network Tutorial2. 3.01 How Networks Work3. 3.01 History and Internet Dropbox4. 3.02 Skills Check 35. 3.02 Boolean QC Chart6. 3.02 How Stuff Works Brain Quiz7. 3.02 Searching the Web Dropbox8. 3.03 Intel Education9. 3.03 Tutorial for Info Power10. 3.03 Side Trip11. 3.03 Evaluating Web Sites Dropbox12. 3.04 On Guard Online Spyware Quiz13. 3.04 Practice14. 3.04 Vocabulary Practice

• So, are you finished?

Unit 3 Internet Basics

Documents

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