Unit 3
Internet Basics
3.04 Malicious Software Can Travel and Spread
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 Security
Definitions
•
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)
Lesson: Computer Security
Definitions
• 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
Lesson: Computer Security
Definitions
• 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
Lesson: Computer Security
Definitions
• 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
Lesson: Computer Security
Definitions
•
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
Lesson: Computer Security
Definitions
•
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.
Lesson: Computer Security
Definitions
•
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.
Lesson: Computer Security
Definitions
• 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.
Lesson: Computer Security
Definitions
• 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.
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14.
•
3.01 Network Tutorial
3.01 How Networks Work
3.01 History and Internet Dropbox
3.02 Skills Check 3
3.02 Boolean QC Chart
3.02 How Stuff Works Brain Quiz
3.02 Searching the Web Dropbox
3.03 Intel Education
3.03 Tutorial for Info Power
3.03 Side Trip
3.03 Evaluating Web Sites Dropbox
3.04 On Guard Online Spyware Quiz
3.04 Practice
3.04 Vocabulary Practice
So, are you finished?