HIGH-RISK EMAIL VIRUS COUNTERMEASURES
One obvious means is the ASCII-only attitude: by-passing attachments,
and using only the ASCII portion of the emails. Notify senders that
instead of sending you heavily formatted word-processor documents they
should send you the text in plain format as a physical continuation of
the email itself. For graphic, voice and other non-textual attachments
you might want to forward all such messages to one address (from, say,
all computers in the office), and then open these files on a dedicated
'empty' computer which does not have 'beef' to be destroyed. Don't open
the attachments directly, file them first, make copies of these files,
and then open them with the intended application and watch for any strange
behavior. When the attachments open regularly, and seem clean you might
want then to save them in a format consistent with a former version of
the same software. This toning-down of the file has a good chance to
destroy stubborn virus strains that survived the screening so far, and
remain attached to the graphic, voice, or spreadsheet file, waiting to be
reloaded to a full fledged environment when they can do their damage. Once
the file is saved in a lower version format, it can be reopened in the
higher level format and saved at that format with impunity.
Another basic move of defense is to change the standard email software
in the office, or on your personal computer. This is because you may have
become a target by a hacker who knows what email software you are using,
and is tailoring his or her action to that package, and that particular
version. Some careful players read their mail in one system, and send out
in another (at least for some messages) to mislead a would-be hacker.
There is an advantage to using a not-so-popular email version because the
email-viruses are built one upon the other (the hackers have their own R&D).
Most hackers would not bother to look for cracks in an under-popular email
system. In that respect even a lower version of a popular email system
might help.
As a standard operation you may forward all your email to a different
account which you can easily access by ASCII only. This will help you in
case where the virus prevails, your computer, or network is jammed,
inoperative, and the crucial emails you have been waiting for are
inaccessible. If all your incoming mail was automatically copied to
another account, you could read it there using only ASCII. For example you
can copy your messages to a compuserve account, and then access compuserve
through telnet, staying strictly within the ascii format, neutralizing any
negative effect. Compuserve is very well maintained, has good protection
against intrusion by other means, and its ASCII connection if very fast
and efficient. The disadvantage is that compuserve accounts are limited
to 100 messages, and must be purged occasionally for this method to work.
Of course, all major, and well advertised viruses are very quickly met
with virus-killer software. See updated resources list at the top of this
chapter. However, if you are attacked by a lesser known virus, the chances
for off-shelf countermeasure are slim. In these and other cases you may
opt for other software solutions (see above).
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