Experts in combating “spyware” and “adware” are now warning that the
widely publicized security holes that plague Internet Explorer and other Web
browsers may not be the most common ways unwanted software gets into computer
Eric Howes, a frequent contributor to SpywareWarrior.com
and a consultant to antispyware companies, says the media focus on security
holes is overshadowing a larger issue. It’s true that hackers can take advantage
of weaknesses in browsers to secretly install spyware programs on users’ PCs,
Howes agrees. But equally important is the fact that spyware programs are often
installed because users are fooled into clicking “Yes” by dialog boxes that look
like official Windows notices, he says.
Interestingly, Howes asserts that the latest version of Windows XP, which
includes an upgrade called Service Pack 2 (SP2), makes Microsoft’s Internet
Explorer (IE) browser handle such threats better than Firefox, the fast-growing
open-source software distributed by the Mozilla Foundation. Let’s examine this
How Spyware Tricks Users Into Installing It
The Firefox browser offers at least four ways to install new forms of software,
Howes says. He feels two of these ways are fairly safe, while the other two are
open to abuse by spyware authors.
• Setup programs.
These are the most traditional kind of software install. Using a browser, an
executable file is downloaded, saved to disk, and then run once to install an
application. While any program poses potential risks, Howes says, traditional
setup programs at least make themselves visible to the user, who much choose to
• Browser plug-ins.
Plug-ins are programs, such as Macromedia Flash, that enable a browser to
display special content, such as multimedia files. These are also fairly safe in
Firefox, Howes says, because users are presented with information about the
plug-in before installing it, and can read any end-user license agreement (EULA)
associated with it.
Firefox extensions, small programs that may, for example, add a menu item to the
browser, present a more serious problem, Howes maintains. Once a user clicks a
yellow “information bar” at the top of the browser window that offers to install
an extension, they see a dialog box that prompts them to allow the software to
install. This dialog, Howes says, provides no information about the source of
the software, nor does it provide any link to a EULA.
• Java applets.
The greatest risk, Howes warns, comes from the ability of Java applets to
display dialog boxes that look exactly like ordinary Windows notices. Many users
are accustomed to clicking “Yes” when they see a dialog box informing them that,
for example, an updated media player or “codec” is required to play some
requested content. Since Firefox currently displays nothing but the name of a
possibly obscure software company, all too often users click “Yes” without even
reading the information.
To install as many software programs as possible, some adware companies even
make up company names such as “Click Here To Continue.” This name shows up
prominently in Windows dialog boxes, making many users believe they have no
choice but to click “Yes” to complete their task, according to an
by Ben Edelman, a spyware researcher who is currently studying at Harvard Law
How Internet Explorer in XP SP2 Works Differently
With the release of Service Pack 2 for Windows XP in September 2004, Microsoft
made a positive change in the behavior of IE, which is bundled with Windows. “It
took them a number of years to get it,” Howes says, “but they eventually did get
Instead of popping up a dialog box when a Web site tries to install, for
example, an ActiveX program, IE with SP2 now displays a much less intrusive
alert about the situation. “They put it in the Information Bar to take the
dialog boxes out of people’s faces,” Howes notes, “so they don’t feel pressured
into making potentially bad decisions.”
It’s still possible for a user to click IE’s Information Bar, find more
information about software that a Web site wants to install, and click “OK” to
install it. But it’s much less likely. This, hopefully, will prevent many copies
of spyware and adware from being installed.
(Users of Windows XP who haven’t installed SP2, as well as users of Windows 2000
and earlier versions, don’t enjoy even this much protection against trickery,
Adware Publishers Begin Using Java Applets
Adware makers are already distributing files on the Internet that launch Java
applets on Firefox and other Mozilla-based browsers. According to Howes, these
programs include 180search Assistant, istbar, PowerScan, Sidefind, PeopleonPage,
and the YourSiteBar.
Other programs, including iSearch/iDownload, present dialog boxes to Firefox
users through browser extension methods, according to a PDF
statement (page 2, paragraph 3) by Sunbelt Software, an antispyware maker
that has consulted with Howes.
It’s certainly true that computer owners should be able to install just about
any software they want. The problem arises when official-looking dialog boxes
are presented to users, who often see no difference between them and other
Windows dialog boxes that they must click on every day.
Officials of the Mozilla Foundation, which makes the Firefox browser, did not
respond to e-mails seeking comment by press time.
Defending Against Deceptive Dialog Boxes
“The Firefox ‘yellow bar’ gives little notice of what is actually trying to
install itself, and so, in that respect, IE does have some small advantage,”
according to Christopher Boyd, a spyware researcher associated with
Boyd is a Microsoft “Most Valuable Player” for security, an honor the Redmond
company bestows on individuals who aren’t employed by the firm but who play an
important role in educating end users on Web forums and elsewhere.
At the same time, Boyd says, “until Microsoft untangles IE from the operating
system, the number one target for spyware/malware will always be IE. The problem
we have now is that, realizing Windows and IE are becoming more hardened
(coupled with the raft of security tools people now employ), attackers are
simply resorting to cruder methods of attack — namely social engineering and
Company executives can’t expect computer end users to guess correctly when
confronted with Windows dialog boxes urging them to click “Yes,” Boyd states.
“A security professional who neglects the human aspect of an attack is not a
security professional,” he says. “Here’s something that could get to your PC
across almost all browsers, regardless of secure lockdowns. All it took was a
simple click of a ‘Yes’ prompt. And unfortunately, users click ‘Yes’ to things!”
It’s still important for companies to stay current with security patches that
emerge from Microsoft and other software companies. But these patches can’t
prevent spyware and adware from getting into your company’s computers. It’s
equally important for you to guard against dialog boxes, which may seem perfectly
innocent, but can be deceptive. All too often, even the most
careful person will guess wrong.
A big step forward would be for all browser developers to prevent dialog boxes
from being thrust in the face of PC users by Web sites they may visit. If a site
really needs visitors to install a certain piece of software, it
can explain that fact right in its text and provide a dedicated download page.
Until then, I’m afraid the market for spyware and adware removers will continue
An 11-page PDF report Howes prepared for Sunbelt Software on the problem, which was originally scheduled for
publication in March but was never formally released, is available at a
University of Illinois host, where Howes is based.