Spyware software is used to describe a general term that performs certain behaviors such as advertising, collecting personal information or changing the configuration of your computer, usually without having to obtain proper consent for the first time.
Spyware is often associated with software that displays advertisements (called adware) or software that tracks personal or sensitive information.
it does not mean all software which ads or track your online activities is bad. For example, you might sign up for a free music service, but "pay" service by providing targeted advertisements to get. If you are familiar with the conditions and accept them, they decided to give it a fair compromise. You might also agree to follow the company's online activities to determine the ads to show you.
Other types of Spyware change the computer that can be annoying and can cause your computer to slow down or crash.
These programs can change your Web browser home page or search page, or other components of the browser you do not need or want. These programs also make it very difficult to change the settings back to the way they were originally.
The key in all cases is whether or not (or someone who uses your computer) understand what the software will do and have agreed to install the software on your computer.
there are many ways Spyware and other unwanted software can get on your computer. A common trick to secretly install the software during the installation of other software you want such as a music or video file sharing program.
any software secretly gathers user information without the user's knowledge of internet connection usually for advertising purposes. Spyware applications are typically bundled as a hidden component of freeware or shareware programs can be downloaded from the Internet; However, it should be noted that the majority of shareware and freeware applications do not come with spyware. After installation of Spyware monitors a user's activity on the Internet and transmits that information in the background to someone else. Spyware can also gather information about e-mail addresses and even passwords and credit card numbers
apart from the ethics and privacy, spyware steals by the user of the computer's memory resources, as well as eating bandwidth as it sends information back to the spyware home base through the user's Internet connection. Since spyware using memory and system resources, the applications running in the background can lead to system crashes or general system stability.
because spyware exists independent executable programs, they have the ability to monitor keystrokes, scan files on the hard drive, snoop other applications, such as chat programs or word processors, install other spyware programs, read cookies , change the default home page in the web browser, consistently relaying this information back to the spyware author who will not use advertising / marketing purposes or sell the information to another party. Accompanying
licensing agreements with software downloads sometimes warn the user that a spyware program will be installed along with the requested software, but the licensing agreements may not always be read completely because the notice of the spyware installation is often mentioned obtuse, hard to read legal disclaimers.
Examples of spyware
These common spyware programs illustrate the diversity of behaviors found in these attacks. Remember, computer viruses, researchers give names to spyware programs which may not be used for creators. Programs can be grouped into "families", which is the common code, but a common behavior, or "following the money" of apparent financial or business connections. For example, many spyware programs distributed by Claria collectively known as "Gator". Similarly, the programs, which are often installed together may be described as part of the same package spyware, even when they operate separately.
o CoolWebSearch, a group of programs, takes advantage of Internet Explorer vulnerabilities. The packet traffic that advertising websites, including coolwebsearch.com. It displays pop-up ads, rewrites search engine results, and alters the infected computer's hosts file to direct DNS lookups to these sites.
o Internet Optimizer, also known as DyFuCa, redirects Internet Explorer error pages to advertising. When users follow a broken link or enter an erroneous URL, you see a page of advertisements. However, because password-protected Web sites (HTTP Basic authentication) use the same mechanism to HTTP errors, Internet Optimizer makes it impossible for the user password-protected sites.
o Zango (formerly 180 Solutions) transmits detailed information to advertisers websites that users visit. It also alters HTTP requests for affiliate advertisements linked to a site that advertisements make unearned profit of 180 Solutions Company. This will open the pop-up ads that block the Web sites of competing companies.
o HuntBar, aka WinTools or Adware, installed by ActiveX drive-by Web use at affiliated websites or advertisements displayed by other spyware programs-an example of how spyware is to install more spyware. These programs toolbars to IE, track overall browsing behavior, redirect affiliate references, and advertisements.
oZlob trojan, or just Zlob, downloads itself to the computer via an ActiveX codec and reports information back to Control Server. Some information can be as search history, websites visited, and even key strokes.