Adware


Adware, or advertising-supported software, is software that generates revenue for its developer by automatically generating online advertisements in the user interface of the software or on a screen presented to the user during the installation process. The software may generate two types of revenue: one is for the display of the advertisement and another on a "pay-per-click" basis, if the user clicks on the advertisement. The software may implement advertisements in a variety of ways, including a static box display, a banner display, full screen, a video, pop-up ad or in some other form.
The 2003 Microsoft Encyclopedia of Security and some other sources use the term "adware" differently: "any software that installs itself on your system without your knowledge and displays advertisements when the user browses the Internet", i.e., a form of malware.
Some software developers offer their software free of charge, and rely on revenue from advertising to recoup their expenses and generate income. Some also offer a version of the software at a fee without advertising.
The software's functions may be designed to analyze the user's location and which Internet sites the user visits and to present advertising pertinent to the types of goods or services featured there.

Advertising-supported software

In legitimate software, the advertising functions are integrated into or bundled with the program. Adware is usually seen by the developer as a way to recover development costs, and to generate revenue. In some cases, the developer may provide the software to the user free of charge or at a reduced price. The income derived from presenting advertisements to the user may allow or motivate the developer to continue to develop, maintain and upgrade the software product. The use of advertising-supported software in business is becoming increasingly popular, with a third of IT and business executives in a 2007 survey by McKinsey & Company planning to be using ad-funded software within the following two years. Advertisement-funded software is also one of the business models for open-source software.

Application software

Some software is offered in both an advertising-supported mode and a paid, advertisement-free mode. The latter is usually available by an online purchase of a license or registration code for the software that unlocks the mode, or the purchase and download of a separate version of the software.
Some software authors offer advertising-supported versions of their software as an alternative option to business organizations seeking to avoid paying large sums for software licenses, funding the development of the software with higher fees for advertisers.
Examples of advertising-supported software include Adblock Plus, the Windows version of the Internet telephony application Skype, and the Amazon Kindle 3 family of e-book readers, which has versions called "Kindle with Special Offers" that display advertisements on the home page and in sleep mode in exchange for substantially lower pricing.
In 2012, Microsoft and its advertising division, Microsoft Advertising, announced that Windows 8, the major release of the Microsoft Windows operating system, would provide built-in methods for software authors to use advertising support as a business model. The idea had been considered since as early as 2005.

Software as a service

Support by advertising is a popular business model of software as a service on the Web. Notable examples include the email service Gmail and other Google Apps products, and the social network Facebook. Microsoft has also adopted the advertising-supported model for many of its social software SaaS offerings. The Microsoft Office Live service was also available in an advertising-supported mode.
In the view of Federal Trade Commission staff, there appears to be general agreement that software should be considered "spyware" only if it is downloaded or installed on a computer without the user's knowledge and consent. However, unresolved issues remain concerning how, what, and when consumers need to be told about software installed on their computers for consent to be adequate. For instance, distributors often disclose in an end-user license agreement that there is additional software bundled with primary software, but some panelists and commenters did not view such disclosure as sufficient to infer consent to the installation of the bundled software.

Malware

The term adware is frequently used to describe a form of malware which presents unwanted advertisements to the user of a computer. The advertisements produced by adware are sometimes in the form of a pop-up or sometimes in an "unclosable window".
When the term is used in this way, the severity of its implication varies. While some sources rate adware only as an "irritant", others classify it as an "online threat" or even rate it as seriously as computer viruses and trojans. The precise definition of the term in this context also varies. Adware that observes the computer user's activities without their consent and reports it to the software's author is called spyware. However most adware operates legally and some adware manufacturers have even sued antivirus companies for blocking adware.
Programs have been developed to detect, quarantine, and remove advertisement-displaying malware, including Ad-Aware, Malwarebytes' Anti-Malware, Spyware Doctor and Spybot – Search & Destroy. In addition, almost all commercial antivirus software currently detect adware and spyware, or offer a separate detection module.
A new wrinkle is adware that disables anti-malware and virus protection; technical remedies are available.
Adware has also been discovered in certain low-cost Android devices, particularly those made by small Chinese firms running on Allwinner systems-on-chip. There are even cases where adware code is embedded deep into files stored on the system and boot partitions, to which removal involves extensive modifications to the firmware.