Well, I'm also an attorney, and a very heavy user of Word. The overwhelming majority of attorneys use Word just about all day, every day.
You've been told that there are "no viruses for the Mac" in this thread. Assuming that one is using "virus" to mean "malware", which is how most of the world defines it, then that is patently false and I wish that folks who should know better would stop saying that. At minimum, it is a misleading statement. There
is definitely malware for the Macintosh. It may not technically be a virus, because it does not self-replicate, and it may be incredibly uncommon, but malware for the Macintosh
does exist.
Microsoft Word is a special target. Because most versions of Word include Visual Basic for macros, "Word macro viruses" used to be wildly common. What you described sounds typical of the type of havoc that a Word macro virus used to cause. Your client may have encountered one.
Why aren't they wildly common anymore? It's not because they have been stamped out. It's because Word has what is known as "Macro Virus Protection" built-in. But...it doesn't work unless it is turned on
AND the warnings it sends out are heeded.
To make sure that it is turned on, go to:
In Word:
Word menu --> Preferences --> Security & Privacy --> select: Disable all macros with notification
Now, when you receive a file that has a macro in it, you will get a notice to that effect when you go to open the file. DO NOT allow the macro to run unless you are 100% sure that the file is from a trusted source and that it is supposed to have a macro in it.
support.microsoft.com