Computer viruses are malicious computer programs (‘malware‘) that get installed on a computer and either do things or take things that are not in the computer user’s best interests.

Adware

Adware, or advertising-supported software, is any software package which automatically renders advertisements or comes bundled with additional software in order to generate revenue for its author. Often there is a poorly visible tick box or button that allows the user to skip the installation of the revenue raising bundled software. Advertisements may be in the user interface of the software or on a screen presented to the user during the installation process. The term is sometimes used to refer to software that displays unwanted advertisements or comes bundled with additional software.

Bloatware

Although not malicious nor being a virus, bloatware is worth mentioning as it often does not have the best interests of the computer user at heart.  Bloatware is a piece of software, hardware or website that attempts to do too much and becomes utterly useless for users. An example of bloatware would be a word processing application that also tries to be your page layout program, drawing tool, and web browser; absorbing half your hard drive and all your RAM in the process.  You don’t need a virus scanner to detect bloatware; you simple uninstall the software when you find it does not do (well) what it initially promised. Bloatware often has a strong commercial focus with a goal of raising revenue.

Browser hijack

A browser hijacker is a type of malware designed to change your internet browser’s settings. A browser hijacker changes your web browser’s home page and default search provider to a different one without your permission.

Ransomware

Ransomware is a type of malware which restricts access to the computer system that it infects, and demands a ransom paid to the creator(s) of the malware in order for the restriction to be removed. Some forms of ransomware encrypt files on the system’s hard drive, while some may simply lock the system and display messages intended to coax the user into paying.

Phishing

Phishing is the attempt to acquire sensitive information such as usernames, passwords, and credit card details (and sometimes, indirectly, money) by masquerading as a trustworthy entity. Phishing is typically carried out by email or instant messaging and it often directs users to enter details at a fake website whose look and feel are almost identical to the legitimate one. Phishing is an example of social engineering techniques used to deceive users.

Rootkit

A rootkit is a stealthy type of software, typically malicious, designed to hide the existence of certain processes or programs from normal methods of detection and enable continued privileged access to a computer.  This type of software often exploits holes in computer security and requires special software to remove.

Spyware

Spyware is software that aims to gather information about a person or organization without their knowledge and that may send such information to another entity without the consumer’s consent, or that asserts control over a computer without the consumer’s knowledge. Spyware is mostly classified into four types: system monitors, trojans, adware, and tracking cookies. Spyware is mostly used for the purposes of tracking and storing Internet users’ movements on the Web and serving up pop-up ads to internet users.

Trojan

A Trojan Horse, or Trojan, is a malicious program or bit of software masquerading as a useful, popular or interesting program.  Often the program runs as intended, but launches a small hidden program in the background. A Trojan often acts as a backdoor, contacting a controller which can then have unauthorized access to the affected computer. While Trojans and backdoors are not easily detectable by themselves, computers may appear to run slower due to heavy processor or network usage. Malicious programs are classified as Trojans if they do not attempt to inject themselves into other files (computer virus) or otherwise propagate themselves. A computer may host a Trojan via a malicious program that a user is duped into executing (often an e-mail attachment or a file download from a web page disguised to be unsuspicious).

Worm / Botnet

A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. Worms are like a vessel to infect other computers; once infected, the worm may launch a malicious program called the payload. A very common payload for worms is to install a backdoor in the infected computer to allow the creation of a “zombie” computer under control of one or more master computers. Networks of such machines are often referred to as botnets and are very commonly used by spam senders for sending junk email or to cloak their website’s address.

Zero Day vulnerability

A zero day vulnerability refers to a hole in software that is unknown to the vendor. This security hole is then exploited by hackers before the vendor becomes aware and hurries to fix it—this exploit is called a zero day attack.

Identity theft

Identity theft is a form of stealing someone’s identity in which someone pretends to be someone else by assuming that person’s identity, usually as a method to gain access to resources or obtain credit and other benefits in that person’s name. Identity theft occurs when someone uses another’s personally identifying information, like their name, identifying number, or credit card number, without their permission, to commit fraud or other crimes.

Data mining

While the term “data mining” itself has no ethical implications, it is often associated with the mining of information in relation to peoples’ behavior (ethical and otherwise). The ways in which data mining can be used can in some cases and contexts raise questions regarding privacy, legality, and ethics. In particular, data mining government or commercial data sets for national security or law enforcement purposes has raised privacy concerns. Data mining may use data aggregation.  Data aggregation involves combining data -possibly from various sources- together. The threat to an individual’s privacy comes into play when the compiled data is able to identify an individual, especially when the data were originally anonymous.

Data may also be modified so as to become anonymous, so that individuals may not readily be identified. However, even “de-identified”/”anonymized” data sets can potentially contain enough information to allow identification of individuals.