What are viruses?
A computer virus is a program that spreads by first infecting files or the
system areas of a computer or network router's hard drive and then making
copies of itself. Some viruses are harmless, others may damage data files, and
some may destroy files. Viruses used to be spread when people shared floppy
disks and other portable media, now viruses are primarily spread through email
Unlike worms, viruses often require some sort
of user action (opening an email attachment or visiting a malicious web
page) to spread.
What is a worm?
A worm is a type of virus that can spread without human interaction. Worms
often spread from computer to computer and take up valuable memory and network
bandwidth, which can cause a computer to stop responding. Worms can also allow
attackers to gain access to your computer remotely.
What is a Trojan horse?
A Trojan horse is a computer program that is transporting a virus or other
potentially damaging program. A Trojan horse can be a program that purports to
do one action when, in fact, it is performing a malicious action behind the
scene on your computer. Trojan horses can be included in software that you
download for free or as attachments in email messages. They also can be set to
activate at a later date.Making it
nearly impossible to track where it came from.
Can I get a virus by reading my
Most viruses, Trojan horses, and worms are activated when you open an
attachment or click a link contained in an email message. If your email client
allows scripting, then it is possible to get a virus by simply opening a
message. It's best to limit what HTML is available in your email messages. The
safest way to view email messages is in plain text.
How to avoid getting a virus
infection via email?
Most e-mail viruses come from opening and running unknown email attachments. Never open anything that is attached to
an email message unless you know the
contents of the file. If you receive an attachment from a familiar email
address, but were not expecting anything, you should contact the sender before
opening the attachment. If you receive a message with an attachment and you do not recognize the sender, you
should delete the message.
Some handy tips:
Install anti-virus software from a
reputable vendor. Update it and use it regularly.
Use a virus scan
before you open any new programs or files that may contain executable code.
This includes packaged software that you buy from the store as well as any
program you might download from the Internet.
If you are a member
of an online community or chat room, be very careful about accepting files or
clicking links that you find or that people send you within the community.
Make sure you back up your data (documents, bookmark
files, important email messages, etc.) on disc so that in the event of a virus
infection, you do not lose valuable work.