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National Cyber Alert System
Cyber Security Tip ST04-016
Recognizing and Avoiding Spyware
Because of its popularity, the internet has become an ideal target for
advertising. As a result, spyware, or adware, has become increasingly
prevalent. When troubleshooting problems with your computer, you may
discover that the source of the problem is spyware software that has been
installed on your machine without your knowledge.
What is spyware?
Despite its name, the term "spyware" doesn't refer to something used by
undercover operatives, but rather by the advertising industry. In fact,
spyware is also known as "adware." It refers to a category of software that,
when installed on your computer, may send you pop-up ads, redirect your
browser to certain web sites, or monitor the web sites that you visit. Some
extreme, invasive versions of spyware may track exactly what keys you type.
Attackers may also use spyware for malicious purposes.
Because of the extra processing, spyware may cause your computer to become
slow or sluggish. There are also privacy implications:
* What information is being gathered?
* Who is receiving it?
* How is it being used?
How do you know if there is spyware on your computer?
The following symptoms may indicate that spyware is installed on your
computer:
* you are subjected to endless pop-up windows
* you are redirected to web sites other than the one you typed into your
browser
* new, unexpected toolbars appear in your web browser
* new, unexpected icons appear in the task tray at the bottom of your
screen
* your browser's home page suddenly changed
* the search engine your browser opens when you click "search" has been
changed
* certain keys fail to work in your browser (e.g., the tab key doesn't
work when you are moving to the next field within a form)
* random Windows error messages begin to appear
* your computer suddenly seems very slow when opening programs or
processing tasks (saving files, etc.)
How can you prevent spyware from installing on your computer?
To avoid unintentionally installing it yourself, follow these good security
practices:
* Don't click on links within pop-up windows - Because pop-up windows are
often a product of spyware, clicking on the window may install spyware
software on your computer. To close the pop-up window, click on the "X"
icon in the titlebar instead of a "close" link within the window.
* Choose "no" when asked unexpected questions - Be wary of unexpected
dialog boxes asking whether you want to run a particular program or
perform another type of task. Always select "no" or "cancel," or close
the dialog box by clicking the "X" icon in the titlebar.
* Be wary of free downloadable software - There are many sites that offer
customized toolbars or other features that appeal to users. Don't
download programs from sites you don't trust, and realize that you may
be exposing your computer to spyware by downloading some of these
programs.
* Don't follow email links claiming to offer anti-spyware software - Like
email viruses, the links may serve the opposite purpose and actually
install the spyware it claims to be eliminating.
As an additional good security practice, especially if you are concerned
that you might have spyware on your machine and want to minimize the impact,
consider taking the following action:
* Adjust your browser preferences to limit pop-up windows and cookies -
Pop-up windows are often generated by some kind of scripting or active
content. Adjusting the settings within your browser to reduce or prevent
scripting or active content may reduce the number of pop-up windows that
appear. Some browsers offer a specific option to block or limit pop-up
windows. Certain types of cookies are sometimes considered spyware
because they reveal what web pages you have visited. You can adjust your
privacy settings to only allow cookies for the web site you are visiting
(see Browsing Safely: Understanding Active Content and Cookies and
Evaluating Your Web Browser's Security Settings for more information).
How do you remove spyware?
* Run a full scan on your computer with your anti-virus software - Some
anti-virus software will find and remove spyware, but it may not find
the spyware when it is monitoring your computer in real time. Set your
anti-virus software to prompt you to run a full scan periodically (see
Understanding Anti-Virus Software for more information).
* Run a legitimate product specifically designed to remove spyware - Many
vendors offer products that will scan your computer for spyware and
remove any spyware software. Popular products include Lavasoft's
Ad-Aware, Microsoft's Window Defender, Webroot's SpySweeper, and Spybot
Search and Destroy.
* Make sure that your anti-virus and anti-spyware software are compatible
- Take a phased approach to installing the software to ensure that you
don't unintentionally introduce problems (see Coordinating Virus and
Spyware Defense for more information).
_________________________________________________________________
Authors: Mindi McDowell, Matt Lytle
_________________________________________________________________
Copyright 2004 Carnegie Mellon University. Terms of use
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