 |
 |
 |
 |
 |
Spyware ... Part 2
Consequences
Windows-based computers, whether used by children or by adults, can sometimes rapidly accumulate a great many spyware components. The consequences of a moderate to severe spyware infection (privacy issues aside) generally include a substantial loss of system performance (over 50% in extreme cases), and major stability issues (crashes and hangs). Difficulty in connecting to the Internet also commonly occurs as some spyware (perhaps inadvertently) modifies the DLLs needed for connectivity.
As of 2004, spyware infection caused more visits to professional computer repairers than any other single cause. In more than half of these cases, the user has no awareness of spyware and initially assumes that the system performance, stability, and/or connectivity issues relate to hardware, Windows installation problems, or a virus. (On the other hand, older versions of Windows itself, as well as CPU undercooling, can manifest spyware-like symptoms, specifically including instability or slowness.)
Some spyware products have additional consequences. Stealth dialers may attempt to connect directly to a particular telephone number rather than to a user's own intended ISP: where connecting to the number in question involves long-distance or overseas charges, this can result in massive telephone bills which the user has no choice but to pay.
Some other types of spyware (Targetsoft, for example) even go to the extent of modifying system files to make themselves harder to remove. (Targetsoft modifies the Winsock (Windows Sockets) files. The deletion of the spyware-infected file "inetadpt.dll" will interrupt normal networking usage.)
Installation
Spyware normally installs itself through one of a number of methods:
The spyware component comes bundled with an otherwise apparently useful program. The makers of such packages usually make them available for download free of charge, so as to encourage wide uptake of the spyware component. This applies especially with file-sharing clients such as Kazaa and earlier versions of Bearshare.
The spyware takes advantage of security flaws in Internet Explorer. Internet Explorer can also install spyware on your computer either via a drive-by download with or without any prompt. A drive-by download takes advantage of easy installation via an ActiveX control (or several ActiveX components) with or without a prompt, depending on security settings within Internet Explorer. Pop-up windows are often associate with this type of transfer of spyware to your system. If you encounter pop-ups while browsing close them only by clicking on the X at the top right of the window or by pressing Alt-F4 on the keyboard. Never click on any text within the pop-up window itself.
Spyware can also install itself on a computer via a virus or an e-mail trojan program, but this does not commonly occur.
An HTTP cookie, a well-known mechanism for storing information about Internet users on their own computers, often stores an individual identification number for subsequent recognition of a website visitor. However, the existence of cookies and their use generally does not hide from users, who can also disallow access to cookie information. Nevertheless, to the extent that a Web site uses a cookie identifier (ID) to build a profile about the user, who does not know what information accumulates in this profile, the cookie mechanism could count as a form of spyware. For example, a search engine website could assign an individual ID code to a user the first time he or she visits and store all search terms in a database with this ID as a key on all subsequent visits (until the expiry or deletion of the cookie). The search engine could use this data to select advertisements to display to that user, or could — legally or illegally — transmit derived information to third parties.
Granting permission for web-based applications to integrate into one's system can also load spyware. These Browser Helper Objects — known as Browser Hijackers — embed themselves as part of a web browser.
Spyware usually installs itself by some stealthy means. User agreements for software may make references (sometimes vague) to allowing the issuing company of the software to record users' Internet usage and website surfing. Some software vendors allow the option of buying the same product without this overhead.