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How do I Protect Myself from Viruses?
This document is intended to help CSN staff and students to protect themselves against
computer viruses, worms, and other forms of malicious code. Note that suggestions regarding
external services and products are provided for your convenience and should not be regarded
as endorsements or guarantees of reliability. The following topics are presented here:
- What is a virus?
- What do viruses do?
- How should I protect myself?
- I think I received a virus in my e-mail. What should I do?
- Where can I find the latest news about viruses?
- Can I be notified automatically when there is a threat?
- Is virus protection software available?
- I have the anti-virus software installed, is my computer safe now?
- How do I update my virus protection? How often?
- How can I tell if it's a hoax?
- What other resources are available?
- How do I get help?
What is a virus?
Essentially it is a program or piece of software code that is loaded onto your computer without your
knowledge and run against your wishes. Most viruses also have an ability to replicate themselves. All
computer viruses are manmade. A simple virus that can make a copy of itself over and over again is
relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all
available memory and bring the system to a halt. An even more dangerous type of virus is one capable
of transmitting itself across networks and bypassing security systems.
The use of a good anti-virus program has become a necessity. These programs can be used to
periodically check your computer system for the best-known types of viruses. Some people
distinguish between general viruses and worms. A worm is a special type of virus that can replicate
itself and use memory, but cannot attach itself to other programs.
What do viruses do?
Most viruses are comparatively harmless, and may be present for years with no noticeable effect:
some, however, may cause random damage to data files (sometimes insidiously, over a long period)
or attempt to destroy files and disks. Others cause unintended damage. Even benign viruses
(apparently non-destructive viruses) cause significant damage by occupying disk space and/or main
memory, by using up CPU processing time, and by the time and expense wasted in detecting and
removing them." (Source: excerpted with permission from the Virus FAQ.)
Many viruses are disguised in e-mail attachments with an interesting name. When a curious
computer user receives the mail and opens the attachment, the virus attempts to modify the registry in
order to copy itself into the Windows directory. The virus will then attempt to send infected mail
messages to all addresses in the Windows Address Book. Other viruses may be ‘caught’ by using
suspect web-sites.
By causing congestion through self-propagation, a virus can also cause mail server performance
problems. Be advised that the subject line and attachment name may change as the virus spreads!
Macro viruses are becoming an increasing threat for users of Microsoft Office products such
as MS-Word, MS-Excel, and MS-Powerpoint.
So how should I protect myself?
The simplest solution is to ensure that you have anti-virus protection software installed (you should
notice that NOD32 is preinstalled on the college computers). Also be sure to scan any removable
media disks you are using prior to use (the NOD32 software should do this automatically for you for
example, but not all anti-virus software will do so). For instance, if you are using a USB flash drive
on one of the college desktops, always ensure that you scan the disk before you open any files on it.
Remember, the primary responsibility for ensuring you do not contract a computer virus or
spread/infect other computers with a virus lies with you!
If you have anti-virus software installed on your computer at home, make sure that you update the
software regularly! If the anti-virus software is already up-to-date you should see a dialog box
confirming this. In this case you need not do anything more, otherwise update immediately.
Even if you have an up-to-date anti-virus software package installed, you may still be at risk from
malware. An increasing number of viruses cannot be ‘cleaned’ by simply running the latest anti-virus
checker. If you are already infected, preventing further infection is the wisest course of action.
Some simple guidelines for you to follow:
- Scan your files/disks for viruses at regular intervals
- Be very careful when using/opening e-mail attachments
- NEVER open any e-mail attachment unless you are expecting the file and know it is from a
reliable source, especially if you are using Windows OS
- Always, always back up your files – then back-up the back-up!
- Stay informed, try to keep up with the latest news about viruses
- Don't spread rumours or pass along unverified notices regarding computer viruses. If you are in
doubt, alert the IT department immediately
- If your home system/flash USB drive is already infected, try to get professional help if necessary
- If you are at CSN and you receive an email that you believe contains a virus, or think your
machine may already be infected with a virus, contact the IT department immediately
I think I might have received a virus in my e-mail. What should I do?
First, never open the attachment unless you are absolutely sure it is from a reliable source. Often
infected e-mail messages invite you to click on an attached file and/or link. Don't be tempted! The
Attachments/links are most likely virus executables that will infect the computer. In some cases it's
easy to see that the message is just "junk" mail. But messages often appear to originate from an
‘official’ source such as Microsoft, AIB, etc. Just remember that official sources never send important
data or software patches as e-mail attachments. If you are in doubt about any message you receive,
contact the IT department.
Where can I find the latest news about viruses?
There are many ways to find out about the latest viruses on the Internet. Some web sites provide
general information, while others are more technical. We recommend that you try to familiarise
yourself with a few of them and use the sources that are most helpful and convenient. A continuously
updated list of the latest threats is always provided at
http://www.f-secure.com/v-descs/i.shtml
Can I be notified automatically when there is a threat?
Yes. We will endeavour to inform you via email about the most serious threats. Please provide
information about your web-based email account if you wish to avail of this service via virus
alerts@csn.ie.
Where can I get free antivirus software?
Many vendors offer free or ‘lite’ versions of their anti-virus software for use on home computers only.
Two popular versions may be downloaded via one of the following links
I have anti-virus software installed, is my computer safe now?
Not necessarily. As we have said you will still need to download updates regularly. Most experts
recommend that you download updates at least once a week, and more frequently if you hear
that a virus is spreading.
How do I update my virus protection? How often?
Immediately after installation and periodically thereafter you should run the Virus Update feature, a
component of the software, to update your virus definition files. Failure to update your virus
definition files will leave your computer vulnerable to new viruses. If you are a member of staff with
a dedicated office space you may do this yourself by following the directions given.
How can I tell if it's a hoax?
You can’t. Hoaxes normally involve phoney announcements, warnings, or instructions. One recent
type of hoax involves e-mail that purports to come from an official source, but is in fact a virus. Often
infected e-mail messages that appear to originate from an official source such as Microsoft invite you
to click on an attached file. You should never do this.
If you receive an e-mail message that suggests you forward it to everyone you know, it's very
probably either a hoax or a chain letter. Distributing chain letters is against CSN policy, so don't send
these messages to others. Before distributing some dire warning to all of your friends or mailing lists,
we recommend that you make sure it is not a hoax. Here are sources of information about hoaxes and
myths:
What other resources are available?
To learn more about viruses and how they work, check the alt.comp.virus FAQ.Check Google groups
for Usenet discussion forums on computing and other issues. See the Stay Safe Online Web site for
additional tips on computer security. How do I get help?
To get assistance with a virus infection, contact the IT department in the first instance or check the
relevant web sites.
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