Malware (short for malicious software) is a term coined to describe programs which are ultimately detrimental to the computing experience. Viruses are the most visible and publicized malware but there are other types, specifically adware and spyware, which are less obviously a threat but perhaps even more of a nuisance. This page will describe the various types of malware and what steps should be taken to remove them or, if possible, prevent their installation.
A virus is a computer program designed to install itself on a computer
without the user’s knowledge and then perform some task. Most commonly
viruses will try to infect other machines, open up the infected machine to
outside access or cause damage to files. A worm typically is installed when
a user launches an infected e-mail attachment. The worm then uses the mail
system (and address books) of the infected computer to send infected e-mails
to other users.
This type of malware is very high-profile with several companies such as
Network Associates (McAfee) and Symantec (Norton) actively working to combat
it. Using a virus-scan product and keeping current with Windows Updates are
the best methods available to prevent infections. Users should also be wary
of unexpected e-mail attachments, even if they come from someone they know.
More information on viruses and methods of prevention can be found at the
OIT Virus and Security
Alerts website.
Adware is software which is free to the user or available at a reduced cost
because it displays advertisements either in the software window itself or
in separate pop-up windows. By itself adware is merely irritating as the
user must contend with unwanted pop-up windows while running the
ad-supported software.
Spyware is any software which utilizes the bandwidth of the machine on which
it is installed to communicate with the parent company. Statistics about
one’s browsing habits, installed software and other information are
collected by these companies and then either sold as market research or used
by the company itself to target ads at the user.
Together (often a program works as both adware and spyware) they represent a
serious invasion of the user’s privacy and could use up considerable
bandwidth and processor resources communicating with the developer and
downloading ad content.
It is often difficult to identify this software without a thorough reading
of the end user license agreement. Companies which distribute this software
use many tricks to entice users to install their programs. Two common
channels by which malware is installed are pop-ups which look like a
security warning and opt-out installers. Users should familiarize themselves
with these methods and use discretion when agreeing to anything on the web.
Spoofed Security Warnings – Some malware installation requests are designed
to look like a typical security request from the browser. The tendency is
for people to accept anything that pops up which they feel is restricting
them from viewing a particular page. When a user clicks yes, thinking they
are accepting a security certificate, they actually are giving permission to
install whatever software the distributor wishes to push to their computer.
To prevent these installations one only has to read carefully any requests
that pop-up while browsing and make sure they are indeed required. If you
are unsure, answer no and then if you have problems with that particular web
page, go back and answer yes when the request appears.
Opt-out Installers – Some web-sites which require a user registration
include opt-out installers for various pieces of adware and spyware. An
opt-out installer is one such that if you do not explicitly decline whatever
software they are offering, it will be installed by default once you
complete your registration for the site. The tools to decline the
installation are often deliberately inconspicuous and typically the
installation happens without the user’s knowledge. Opt-out installers are
also seen quite often in the installation packages for “free” software such
as screen-savers, download managers, games, shopping assistants and web
accelerators.
Users are not often aware that their machine is host to malware until it
begins to affect performance. Excessive pop-ups or slow network access may
be the only indication that the computer has been “infected”.
As the old saw goes, an ounce of prevention is worth a pound of cure. Users
should take the following steps to be sure their machines are as secure as
possible:
• Keep Windows up to date – Use the Windows Update feature of your operating
system to be sure you have all of the most recent security and functionality
updates.
• Keep anti-virus software current – Users should be running an anti-virus
package such as McAfee VirusScan which continually scans the computer for
viruses and other threats. It is vital that the virus information be kept up
to date; otherwise its effectiveness will be greatly diminished.
• Install and configure a firewall – Install a personal firewall product
such as ZoneAlarm or enable Internet Connection Firewall under Windows XP to
monitor and block internet traffic.
For the removal of spyware, OIT recommends and uses a program called SpyBot
Search and Destroy. Freely available from
http://security.kolla.de, users may install and run this software which
scans their machine for known spyware, adware and tracking information. It
works similarly to a virus scanner and will recognize and eliminate the vast
majority of spyware programs.
New malware threats appear almost daily so it is important that users take
the time to become familiar with the information and tools which are
available to combat the problem. Below is a list of links to many resources
related to the problem of malware.
http://malwarebytes.org
At this site, you can obtain a free version of a malware removal tool.
http://www.nai.com
The official website for McAfee VirusScan carries alerts about current
threats, a virus information library and many other tools and articles which
will assist one in fighting viruses.
Please see the
Common Malware Programs page for a partial list of software which is
known to include spyware elements. A comprehensive list would not be
possible to produce as new spyware is produced almost daily. Users should
view this list as a warning of the prevalence of this problem and take steps
to keep their machines free from this latest threat to privacy and
productivity.