Can my Mac pass Windows viruses to other Windows machines on the network

Question

System Adm is telling me that I cannot connect my Mac to the school network if I am using a private line that is not passing through the school firewall because I could infect his network. Is that truly the case?
Thanks,
todd

Answer 1

In addition to Graham's excellent information (I may be repeating some of it).
You can spread these by sending infected documents or e-mails to other users.
Completely true. If you receive Windows malware on your Mac via email, it can't do a thing to OS X, but you can infect a Windows user by forwarding that email with the attachment still intact.
Running Microsoft VirtualPC for Mac exposes your Mac to all Windows viruses.
True, but not quite the way it reads. VirtualPC is for running Windows via emulation on your Mac. The Windows environment can be infected the same as any Windows PC. It cannot expose your Mac to those viruses. More specifically, they cannot in any way infect OS X.
Macro viruses, such as those written for Microsoft Office products, can infect your Mac or destroy data.
Yes and no. Macro viruses tag along on infected Word documents. I have yet to see or hear of one that can do anything to OS X. So like email Windows malware, you simply become a carrier. When you get a document with a macro virus and you ignore the warning to open the document without loading the macro, it will infect your Normal document (Office X or 2004) the same as it would in Windows. From then on, Word on your Mac will infect all documents you save. One way to avoid that is to set the preferences in Office to never load macros. The other is to disallow macros to load when you open any document that has one (Word will ask you what you want to do). If Office 2008, macros have been removed from the program. You can't infect any new documents, but I don't know if opening a file that already carries macros will be stripped. It may just save them with the file again when you save an existing file with your changes. As far as the last point? No, Word macros cannot destroy data on your Mac. They are all written for Windows and will not run in OS X any more than a Windows program can.
Implementing Boot Camp and installing Microsoft Windows on your Intel®-based Mac exposes that computer to the same threats as running Windows on a PC.
Completely true. Windows is Windows. The hardware it's running on makes no difference. The Windows partition on your Mac will be exposed to all Windows malware as a Dell would be.