Once
again, I would like to remind you about the importance of protecting
your files against computer viruses. You CAN lose your work because
of a virus! You are advised to read this message carefully in its entirety.
While
it is true that there are relatively few Mac viruses, there is
a real threat from Microsoft Office macro viruses. There are thousands
of them and they are cross-platform, i.e. they work on Macs and
PCs! These viruses will not wipe out your entire hard disk or
cause a damage to your ROM (at least not now) but they can cause
enough damage for you to be really concerned. They can delete
or scramble your files for instance, which is pretty bad.
What
is a Macro?
A
macro is a series of commands to perform some application-specific
task. Macros are designed to make life easier; for example, to
perform some everyday tasks like text-formatting or spreadsheet
calculations. Macro viruses are malicious macros that are executed
automatically at a specific time. For instance they run when you
open or close a document (such macros are AutoOpen, AutoClose,
AutoExec and AutoExit). They can also get executed when user performs
a specific action, such as Save or SaveAs from the menu or by
a key shortcut. They can also be triggered by another macro. Even
if a virus does not affect your Mac directly, you could pass it
to another PC/Mac user without even realizing it. You may then
receive a message from your recipients telling you that your attachments
contained viruses that caused damage to their vital files!
These
viruses can find their way to your computer in several ways:
They
can be e-mailed to you as an attachment: a word document, a spreadsheet
or a presentation. They
may be embedded in a HTML formatted message. You
can download them from a website or an ftp server. You
can copy them from a network volume, i.e. a network server or
another computer. You
can bring them in on a floppy, ZIP, Jaz, MO, DVD or any other
removable media including CD-ROM discs!
You should exercise caution when opening attachments even if you
received them from trusted colleagues or friends. They may not
be aware that they've e-mailed you a virus!
Microsoft
Office 98 has macro virus protection built in that detects any
macros when you open a document. It will give you an option then
to enable or disable the macros(s). If you know that the document
is not supposed to have any macros in it, yet Microsoft Office
98 warns you about a presence of a macro, it is a good chance
that your file is infected with a macro virus! Unfortunately,
some documents have useful macros built-in and disabling all macros
will render the document useless.
Most of the time it is impossible to see and manually delete a
macro virus that has been compiled and embedded into a document
without using antivirus software, because the macro virus may
be protected, encrypted or made stealth. Normally you can see,
edit and delete macros from Microsoft Office 98 document by going
to the menu Tools->Macro->Macros or by using Visual Basic Editor:
Tools->Macro->Visual Basic Editor.
However, macro viruses can be read-only or encrypted and you will
not be able to delete them or edit them with Visual Basic Editor.
All buttons and options will be grayed-out and unavailable. Remember
that these viruses were designed to be annoying, damaging and
hard to deal with! Some of them are so called polymorphic macro
viruses and they alter their own code to appear differently in
different documents, therefore making it more difficult to detect
them. Finally, a macro virus can merge itself into a standard,
seemingly harmless macro
The
most common symptoms of a macro virus infection:
You are
unable to print. Your Microsoft
Office 98 (Word, Excel and Power Point) documents multiply. Your documents
have their names and/or icons changed The contents
of your documents was erased or scrambled. Your documents
become invisible or are moved to another location. Your documents
get deleted. Your documents
become password protected. Your Preferences
get changed.
Additionally, macro viruses can use Internet Explorer and Outlook
Express to attach themselves to your email messages. They can also
use your address book and email damaging or obscene messages. This
has been a little threat to Mac users so far, but nevertheless it
is something to be aware of.
Finally, macro viruses can easily spread and infect more documents,
templates, address books, dictionaries, etc.
It is also important to remember that there are many virus hoaxes.
If you receive an email telling you about some new virus and asking
you to forward it to anyone that you know, it is most likely a hoax
and should be ignored.
We
have a site license for Virex 6.1 for Macintosh OS9. However, like
all antivirus software, Virex needs its virus definitions to be updated
every month. Without the current virus definitions the effectiveness
of Virex is very limited. New viruses are written daily and if Virex
doesn't know about them it will not detect them! These updates must
be applied manually by the user and this process can't be automated
or centralized at this time.
We download the virus definitions update the first week of every month
as it becomes available and place it inside Public Stuff/Antivirus
Stuff on the Public Stuff volume. Also, from now on I will send a
message to all informing that a new virus definitions update is available
in Public Stuff. Sometimes an emergency update is released in the
middle of the month if a major virus is discovered. The recent definitions
are also avilable here
for direct download.
All you need to do is copy the update file to your hard drive and
double click on it to install. It takes about a minute and you do
not need to reboot your Mac.
Using
Virex is very simple. There are guides to Virex
installation and McAfee
VirusScan installations on our site. Virex installs a Virex DropScan
utility right on your desktop. You drag and drop a file, a folder
or an entire disk onto it to scan for viruses. You can also open the
main Virex application and use it to scan your hard disks. In each
case, if Virex finds a virus, it will give you an option to repair
or delete the file. In most instances an infected file can be repaired.
If Virex is unable to repair a file, you should delete the file and
get a new copy.
The current version of Virex is 6.0. If you have an older version,
please get the version 6.0 from Public Stuff/Antivirus Stuff and install
it on your Macintosh.
They
can be e-mailed to you as an attachment: a word document, a spreadsheet
or a presentation.