Spyware is a program subtly installed by spyware developers on computer systems without arising suspicions from the user. Spyware is malicious software designed to manipulate the computer by intercepting or interfering with the user's control and interaction. The purpose of spyware simply surpassed unauthorized monitoring of user's computing behavior. Spyware can be compared with viruses because they are harmful in nature.



Spyware programs are secretly employed to watch the user's activity. It records and accounts on that victim's online movement. They can trail all information related to the user such as personal, psychosocial and demographic details. Spyware also reports on specific website the number of times a user visit that particular site. The information is then used to gather ad impressions target.

Aside from collecting personal inputs on user's Internet browsing habit and websites that been accessed, spyware can intervene with the computer control such as installing other software, rerouting web browser activity, diverting income from advertisements usually to the spyware's author, and blindly and randomly accessing malicious websites.

Spyware can easily change a user's personal settings of a computer leading to slow internet connection speed, various home pages and worse, loss of internet access or other applications. It weakens the computer's defense making the system vulnerable to attacks of viruses, Trojans and other dangerous threats.

They can be unknowingly downloaded from websites, instant messages, email attachments or messages, and file-sharing networks. Spyware can be inadvertently got by accepting a EULA or End User License Agreement from a legitimate software manufacturer.

The term spyware according to record was used on 16th of October 1995. Spyware then meant a hardware used for spying. Nevertheless, during the early part of the year 2000 Gregor Freund of Zone Labs used the term spyware in a press release to denote a rogue application. Since that time, the definition changed.

A survey conducted by the National Cyber-Security Alliance and America Online in 2005 brought about some important figures to the fore.

First to note is that 61% of surveyed computers had spyware. Also, 92% of surveyed users convey they were unaware of the spyware in their computers. And last, 91% accounted that no permission were granted for the installation of the spyware.

Spyware has been one of the leading menaces to computer systems on Windows operating system as of 2006. Computer whose main browser is Internet Explorer are at great risk for its tight consolidation with Windows permits spyware to invade all important components of the operating system. It is also the OS of choice for majority of users.

Users' naiveté about malware and the Internet Explorer's presumption that all ActiveX parts are safe contributed to the widespread of spyware. Prior to the release of Internet Explorer 7, the browser would always display a window for installing any ActiveX component that a site required to install. Spyware also targets the defects in Internet Explorer, Windows and Javascipt to install secretively.

Spyware does not reduplicate or spread like computer worms or viruses do. A computer infected by spyware does not transfer the infection to other; however it breaks through a system by deceiving the user or taking advantage of software glitches. Spyware delude victims by piggybacking on good software or by camouflaging as anti-spyware software or security program, tricking the user to install them.

Spyware by nature uses affected computers for financial profit. Usual tricks to meet this purpose are delivery of unwanted pop-up advertisement; stealing financial information particularly credit card number; tracking of Internet surfing activity for advertising purposes; or directly routing of requests of HTTP to advertising websites. Its distributor normally offers the application as an important utility—like for example as a “Web accelerator” or a useful software agent.