Computer Virus Quiz: Types and Examples

Study Notes

Malicious Software (Malware)

Malware is a term that covers viruses, worms, Trojans, and logic bombs, as well as adware and spyware.
Malware performs actions without the consent or knowledge of the system owner, resulting in a disruptive action or actions.

Categories of Malware

Malware can consume resources and power on a host system or network.
Malware can be used to steal information, such as keyloggers.

Viruses

Viruses are the best-known form of malware.
Viruses are designed to replicate and attach themselves to other files resident on the system.
Viruses require some sort of user action to initiate their infectious activities.

Worms

Worms have the ability to replicate on their own very quickly.
Worms have been responsible for some of the most devastating denial-of-service attacks known.

Trojan Horses

Trojan horses rely on social engineering techniques to start infecting a system and causing harm.
Trojan horses, like viruses, require user action.

Rootkits

Rootkits can hide within the core components of a system and stay undetected by modern scanners.
Rootkits are difficult to detect and even more difficult to remove.

Spyware

Spyware is designed to gather information about a system or a user's activities.
Spyware may even be set up to infect only files of a certain length or type or that start with a certain letter.

Types of Viruses

Companion or camouflage viruses compromise a feature of OSs that enables software with the same name, but different extensions, to operate with different priorities.
Logic bombs are designed to lie in wait until a predetermined event or action occurs.
File or multipartite viruses infect systems in multiple ways using multiple attack vectors.
Shell viruses make the infected program into a subroutine that runs after the virus itself runs.
Cryptoviruses hunt for files or certain types of data on a system and then encrypt it.
Hoax viruses are designed to make the user take action even though no infection or threat exists.

Worms

Worms are malware that is entirely self-replicating.
Worms do not require a host application or user interaction.
Examples of worms include the SQL Slammer worm (2003).

Adware

Adware may replace homepages in browsers, place pop-up ads on a user's desktop, or install items on a victim's system that are designed to advertise products or services.

Virus Creation Process

The creation process involves design, replication, launch, detection, incorporation, and elimination.

Examples of Viruses

The Wabbit virus (mid-1970s) was a replication virus.
The Elk Cloner (1982) was a rapidly spreading virus.
The first PC-compatible virus (1986) infected the boot sector.
The Jerusalem virus (1987) was the first logic bomb, which debuted on Friday the 13th.
Polymorphic viruses (1992) were designed to change their code and shape to avoid detection.

Description

This quiz covers various types of computer viruses, including companion viruses, logic bombs, and more. It explains how they work and their characteristics. Test your knowledge of these malicious software and their impact on computer systems.