Viruses like the 2003 SoBig attack can wreak havoc on your computer
system - at home or at work. To date, more than 60,000 types of
viruses have been defined. While there is no foolproof way for you
to block all viruses, following are a few tips to help you understand
and reduce virus problems.
According to TechWeb, a virus is "Software used to infect
a computer. After the virus code is written, it is buried within
an existing program. Once that program is executed, the virus code
is activated and attaches copies of itself to other programs in
the system. Infected programs copy the virus to other programs."
The effect of the virus may be a simple prank that pops up a message
on screen out of the blue, or it may destroy programs and data.
It can lie dormant and do its damage once a year. For example, the
Michaelangelo virus contaminates the machine on Michaelangelo's
birthday.
Although not the only kind of computer virus, e-mail viruses are
the best known and undoubtedly cause the greatest loss of time and
money overall. An e-mail virus is computer code sent to you as an
e-mail note attachment which, if activated, will cause some unexpected
and usually harmful effect, such as destroying certain files on
your hard disk and causing the attachment to be remailed to everyone
in your address book.
To help protect yourself:
- Install and use anti-virus software to scan any attachment
before you open it. If you're a home or individual user, check
out CNET's reviews
of the top antivirus packages. (Currently, CNET's Editors'
Choice antivirus software is McAfee VirusScan 7.0.) If you're
on a network, check with your network administrator first.
- Obtain the latest upgrades for your operating system,
virus-scanning software, Web browser and email applications. Microsoft
notes that many of their clients aren't downloading and installing
its patches promptly. Visit www.microsoft.com/security/protect
for instructions for your Windows machine.
Frequently visit the Web sites of your software vendors and download
the latest security patches and "virus definitions"
for your virus monitoring software. Configure your virus checker
to scan all incoming email attachments and files that you download
from the Web or from FTP servers and delete all suspicious files.
- Add firewall protection - especially if you have a broadband
connection like DSL or cable modem. Software firewalls are available
to protect personal computers from attack. For a list of software
firewalls for Windows, see www.microsoft.com/security/protect/firewall.asp
- Back up your active files, including important emails,
daily. If your system is attacked, you'll have the data you need
saved and ready to reinstall. You can even copy your data onto
removable media (e.g. floppy disks or CD-ROMs) that you keep in
a separate location. As an added precaution, use two or more backup
disks in case one of the disks fails.
- Be cautious about opening email with attachments you're
not expecting and/or unusual content. Some viruses forge their
return addresses, substituting your friends' (pulled from your
email address book) or even your own. Look at email subject lines
and content to see if it really sounds like the person
you know.
- Urge friends who distribute jokes, political messages and
other messages to place all the addresses in the "blind carbon
copy" (BCC) field. If they include all the addresses
in the "to" field, the widely distributed messages can
unintentionally deliver your email address into the hands of spammers
and virus writers.
- Configure your email application so that:
- Your "list" view reveals which incoming messages have
attached files before you open them.
- Your full name (and not just your email address) automatically
appears in the "from" field in messages you receive
and send. Recipients may not immediately recognize you by your
email address alone, particularly if you have multiple email accounts.
- It does not automatically activate attachments or run JavaScript
or Java applets contained in messages. If you're operating with
Windows, configure it to reveal file extensions. (Check
your software program's "help" options to determine
how to make changes.)
Even friends may unwittingly send a virus that attacks files
on your hard drive or compromises the security of your data. Always
be suspicious of attachments with certain file extensions and
avoid opening (for example, double-clicking on) an e-mail attachment
unless you're expecting it from someone and know what the attachment
contains:
- .bat (batch file, which contains a sequence of commands for
a computer operating system);
- .exe (executable file - a program);
- .pif (program information file containing data to execute an
applicaiton on a Microsoft Windows system);
- .scr (screensaver or script written in Visual Basic or Java);
- .vbs (script file written in Microsoft Visual Basic);
- .hta (HTML file used by viruses to gain access to a computer's
operating system);
- .reg (registration file, which controls aspects of the Windows
operating system or applications).
About viruses, worms and Trojan horses: And you thought we
were talking about illness, bugs and mythology! Computer viruses
are named viruses, worms and Trojan horses because they can replicate
themselves, as biological viruses do. Often concealed within games
or images distributed on the Internet, viruses can modify other
programs and compromise data or your computer's system integrity.
- Computer worms are actual programs that burrow into the active
memory segment of a computer, where they may carry out unauthorized
functions.
- A Trojan horse is not technically a virus because it does not
replicate itself, but it is destructive nevertheless. A Trojan
horse appears to be a benign program, but may alter or destroy
data.
- Because of its prevalence, Microsoft Windows is often the preferred
target of the hackers who produce viruses and worms. The Linux
operating system and Apple Macintosh computers are less likely
to be attacked.
Other resources:
9/03
Sources: www.techweb.com
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