Internet Services Department
Tips for Avoiding Computer Viruses
Dissemination of computer viruses via email attachments is, unfortunately, a way of life. Since much SETI League business is transacted via email, most of our members around the world have received at one time or another, and a few have inadvertantly forwarded onward, harmful or malicious files. The SETI League prohibits the use of attachments in its various email lists. You can help to avoid infection, by observing the following precautions:
- Most of the worms which use e-mail to propagate use Microsoft
Outlook or Outlook Express to spread. If you need to use Outlook,
download and install the latest Outlook security patch from
Microsoft. In general, keep your operating system and applications
up-to-date and apply the latest patches when they become available.
Be sure to get the updates directly from the vendor.
- When possible, avoid e-mail attachments both when sending and
receiving e-mail.
- Configure Windows to always show file extensions. In Windows
2000, this is done through Explorer via the Tools menu:
Tools/Folder Options/View - and uncheck "Hide file extensions for
known file types". This makes it more difficult to for a harmful
file (such as an EXE or VBS) to masquerade as a harmless file (such
as TXT or JPG).
- Never open e-mail attachments with the file extensions VBS, SHS
or PIF.
These extensions are almost never used in normal attachments but
they are frequently used by viruses and worms.
- Never open attachments with double file extensions such as
NAME.BMP.EXE or NAME.TXT.VBS
- Do not share your folders with other users unless necessary.
If you do, make sure you do not share your full drive or your
Windows directory.
- Disconnect your network or modem cable when you're not using
your computer - or just power it down.
- If you feel that an e-mail you get from a friend is somehow
strange - if it is in a foreign language or if it just says odd
things, double-check with the friend before opening any
attachments.
- When you receive e-mail advertisements or other unsolicited
e-mail, do not open attachments in them or follow web links quoted
in them.
- Avoid attachments with sexual filenames. E-mail worms often
use attachments with names like PORNO.EXE or PAMELA_NUDE.VBS to
lure users into executing them.
- Do not trust the icons of attachment file. Worms often send
executable files which have an icon resembling icons of picture,
text or archive files - to fool the user.
- Never accept attachments from strangers in online chat systems
such as IRC, ICQ or AOL Instant Messenger.
- Avoid downloading files from public newsgroups (Usenet news).
These are often used by virus writers to distribute their new
viruses.
