MS Word Viruses

No MS Word viruses will run on (i.e. infect) a Mac however if any did contain a virus and if you then sent a document containing a virus to a PC user then that could infect the PC user if their AV software allowed it. Presumably you are running some sort of AV software on the PC? Run it again, set to scan the docs specifically, (if you can..?) before importing to the powerbook and there shouldn't be any problems.

Beg to differ, some Word macro viruses could cause problems even on a Mac.

There may be an issue of definition here.... what is a virus, what is a trojan, and what is malware?

Let's just say that any machine and/or operating system is vulnerable if the user runs a malicious program.

Microsoft Word is, I believe, configured to tell you if the document you are opening contains macros. If you choose to ignore the warning you are effectively giving the macro permission to run.

All the various protections such as anti-virus software and operating system restrictions do their best to prevent the user unintentionally running malicious code.

No MS Word viruses will run on (i.e. infect)

Sigh. This is incorrect. <http://www.emergency.com/wordvrus.htm>. And in the time since that page went up there have been others.

MS Office macro viruses can affect Macs. I've seen them do this.

There's a reason why pages like this one: <http://apps.carleton.edu/campus/its/training/macrovirus/> exist.

a Mac
however if any did contain a virus and
if you then sent a document containing a virus
to a PC user then that could infect the PC user if
their AV software allowed it. Presumably you are
running some sort of AV software on the PC? Run it
again, set to scan the docs specifically, (if you
can..?) before importing to the powerbook and there
shouldn't be any problems.

There may be an issue of definition here....

No. Some (not all, but some) MS Office macro viruses can affect Macs. Period.

what is
a virus, what is a trojan, and what is malware?

Let's just say that any machine and/or operating
system is vulnerable if the user runs a malicious
program.

Microsoft Word is, I believe, configured to tell you
if the document you are opening contains macros.

If you have the correct settings, yes, it's supposed to do that. However, there are certain macro viruses which were written with knowledge of how MS's macro-blocker works, and circumvent this setting. Some of those macro viruses (not all) can affect Macs. (See <http://ciac.llnl.gov/ciac/bulletins/i-023.shtml>; note that this page was written in 1998, and that since then additional stealth macro viruses have been uncovered.)

If
you choose to ignore the warning you are effectively
giving the macro permission to run.

All the various protections such as anti-virus
software and operating system restrictions do their
best to prevent the user unintentionally
running malicious code.

There are very few new macro viruses produced nowadays. However, there are still a lot of old macro viruses floating around, some of them stealthed, some not. For a long time the virus I saw most often was this one: <http://vil.nai.com/vil/content/v_10132.htm>. I got really sick of fixing people's systems, both Mac and Windows, after they got hit by it.