Security Chapter 5

is a program that looks for known viruses and strives to disable found viruses, by searching a hard drive, and/or by monitoring visited websites and downloaded files.

Antivirus software

_________is software that provides protection against computer viruses and many other forms of malware.

Antivirus software, also known as antimalware,

is the prevention of unauthorized computer access, including viewing, changing, or destroying a computer or data.

Computer security

______________________ involves converting a message into an unreadable form , and converting that message back into a readable form, using secret conversion techniques that only the sender and intended receiver know.

Cryptography

A software firewall prevents all communications with the computer on which the firewall is installed. True/False

False

Antivirus software allows a user to download files from email and websites without worry. True/False

False

Malware is a type of virus. True/False

False

Symmetric-key cryptography ensures only the sender and receiver know the contents of a message. t/f

False

A trojan spreads itself from computer to computer. True/False

False.Unlike viruses and worms, trojan software does not spread itself. Rather, a user intentionally installs the software, believing the software to be safe to use.

A file exhibits suspicious behavior that acts similarly to known infected files, but does not exactly match the behavior of any known viruses.

Heuristic analysis. Antivirus software can use heuristics to analyze the behavior of suspicious files based on the behavior of known viruses.

An _________________ is a dishonest scheme or fraud using the Internet.

Internet scam

____________ is undesired software that is typically installed without a user's knowledge and typically bad for the computer or user.

Malware (short for "malicious software")

___________ is an Internet scam that baits a user to share sensitive information like a password or credit card number.

Phishing

A file exhibits suspicious behavior on a specific user's computer.

Sandbox. Sandboxing in antivirus software allows specific environments to be created for testing a suspicious file's behavior.

Which are ways of improving online account security?

Signing out whenever leaving a computer unattended. Immediately changing passwords if a computer is stolen. For a personal device, enabling a device's screen lock mechanism. Deleting old email messages. Changing passwords frequently.

_______ is unsolicited mass email, perhaps advertising prescription drugs for sale, or further spreading the virus.

Spam

________ is unwanted mass-sent email

Spam

is malware that collects information from a computer without the user's knowledge.

Spyware

_________ is malware that a user installs believing the software to be legitimate or benign, but the software actually has a malicious purpose.

Trojan horse

A common phishing scheme involves emails that inform a user of a frozen financial account, and require the user to provide information to unfreeze the account. True/False

True

A security hole is a weakness in a system that may lead to a security breach. T/F

True

A security hole may exist in software other than just an operating system. True/False

True

A user actually installs trojan software intentionally, not realizing the trojan is malware. T/F

True

Malware is relatively rare on smartphones and tablets compared to desktop computers. True/False

True

Security breaches can be caused by hacks, system glitches, or human error. True/False

True

Spammers may advertise a legitimate business. True/False

True

The difference between a worm and a virus is that a worm doesn't use a host file. True/False

True. A virus is attached to an email, an office document, etc. A worm spreads without such attachment, spreading from computer to computer without requiring user action.

Adware displays advertisements to a user. True/False

True. Adware can be annoying to the user who sees unwanted ads while browsing the web or reading emails, for example, and may slow down a computer also.

_______ helps secure a user's account by requiring the user during sign in to enter a temporary code appearing on the user's mobile phone, which the user usually carries.

Two-step verification

_______ is malware that spreads itself via attachment to a host file, like a biological virus attaches to a human.

Virus

A file is infected with a known virus.

Virus Signature. The virus signatures of known viruses are stored in a database. Antivirus software can use this database to find and eliminate known viruses.

_______is malware that spreads itself without using a host file.

Worm

A legitimate user that tries to access a website that is under a DoS attack might notice _____. a. slow response or no response b. nasty messages from the attacker

a. slow response or no response

_____ is/are unsolicited mass email. a. Spam b. Botnets

a. spam

Which is a common way to obtain a virus? a.Downloading and running an email attachment b.Installing and running purchased software

a.Downloading and running an email attachment

The _____ virus launched a DoS attack against the SCO group in 2004. a.Mydoom b. SOBIG.F

a.Mydoom

In symmetric-key cryptography, the sender and receiver use _____ keys. a.identical b.differing

a.identical. "Symmetric" means both the sender and receiver use the same key.

What is the most common purpose of a virus? a. Damage the computer or data b. Steal information or do illicit task

b. Steal information or do illicit task

How can a browser use a digital certificate to differentiate a legitimate website from one run by a malicious third party? a. The malicious third party website has a digital certificate whereas the legitimate website does not. b. The name of the malicious third party may not match the name provided on the digital certificate. c. The malicious third party has a public key instead of a digital certificate.

b. The name of the malicious third party may not match the name provided on the digital certificate.

A denial of _____ (DoS) attack sends huge numbers of access requests at a coordinated time to one website. a. spam b. service

b.service

A _________ is a large group of infected computers, controlled without the user's knowledge, to perform tasks such as sending spam.

botnet

After a computer is infected with a virus, the user usually realizes within how long? a.Minutes b. Days c. Possibly never

c. Possibly never

Encrypted email messages can be viewed by _____. a. anyone b. anyone with email encryption/decryption software c. a recipient with the appropriate decryption keys

c. a recipient with the appropriate decryption keys

Which website is most likely to have the real purpose of spreading viruses? a.Commercial shopping site b.Free sports article site with ads. c.Free games site

c.Free games site

______ is a program that runs on a user's computer without permission, and spreads itself to other computers, often via email.

computer virus

Cryptography involves converting that message back into a readable form

decryption

A _____________ is achieved by submitting huge numbers of access requests simultaneously to one target website, causing that site's web server to be overloaded, thus preventing legitimate requests from being handled (those requests are "denied service").

denial of service (DoS) attack

A ____________________ is achieved by submitting huge numbers of access requests simultaneously to one website, which overloads that site's web server, thus preventing legitimate requests from being handled (those requests are denied service). Infected computers are commonly used to carry out DoS attacks.

denial of service (DoS) attack

A __________________ is an electronic document that allows a person or organization to securely send and receive data over the Internet.

digital certificate

Cryptography involves converting a message into an unreadable form

encryption

Multiple firewalls should be installed on a system for better security. True/False

false

A _________ is software or hardware that blocks unauthorized communication with a computer while allowing authorized communication over a network.

firewall

malicious security breach done by unauthorized access is often called

hack

A ______ is a number (or text string) used to encrypt or decrypt messages.

key

is a case of unauthorized computer access.

security breach

is an aspect of a computer that can be used to breach security. commonly exist in operating systems.

security hole or vulnerability

A firewall should be used in combination with antivirus software for better security. True/False

true