Symantec Norton Personal Firewall 2003, User Manual

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Understanding Internet risks
Risks from Trojan horses and viruses
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Tracking Internet use
Most browsers pass on information that you might want to keep
confidential. One item that your browser normally passes to Web sites is
the
URL of the page from which you came. This information is used by
some Web sites to help you navigate through the Web site, but it can also
be used to track your Web usage. Norton Personal Firewall blocks this
information.
Your browser also sends information about itself and the operating system
that you are using. While Norton Personal Firewall can block this
information, it is usually used by Web sites to provide Web pages that are
appropriate for your browser.
A more sinister invasion of your privacy is found in programs that you
install on your computer that, without your knowledge, report information
back to Web sites. Several programs that help you download and install
files report your activities over the Internet. Norton Personal Firewall
protects your privacy by alerting you to these communications.
Risks from Trojan horses and viruses
With so many computers connected by networks and the Internet, viruses
can spread more rapidly than they could in the days when files were
transferred from computer to computer on disks. Additionally, the risk has
broadened from viruses to
Trojan horses , worms, and zombies.
A virus is a program or code that replicates by attaching itself to another
program, a boot sector, a partition sector, or a document that supports
macros. Many viruses just replicate, but others do damage. A virus can
arrive in a document that you receive by
email .
A Trojan horse is a program that does not replicate, but damages or
compromises the security of the computer. Typically, it relies on someone
emailing it to you; it does not email itself. A Trojan horse may arrive
disguised as useful software. Some Trojan horses perform malicious
actions on the computer on which they are run, while others, such as Back
Orifice, provide remote control capabilities for
hackers .
A worm is a program that makes copies of itself, for example, from one disk
drive to another, or by sending itself through email. It may do damage or
compromise the security of the computer. A worm can arrive as an
attachment to an email that has a subject that tempts you to open it.