I know this may be a basic topic for many, but always one worth bringing up.
Macro code security in Microsoft Office System 2003 gives you the ability to identify documents with VBA code and make better decisions around whether to trust that code. For instance, if someone sends you a Word document in e-mail that contains a macro, when you open the document, a trust decision must be made on whether to trust the macros contained in the document. You can see what security setting you are running in by clicking on Tools/Macro/Security within your office application. The descriptions in the dialog explain further, but for those of you not looking realtime, I'll summarize here:
If you are running in Very High mode, the code in your document will not run unless you save the document into a trusted location. High mode will force the macros to be digitally signed in order to be enabled. Medium mode will give you a choice when opening the file as to whether you want to enable the macros. If the macros are digitally signed, you'll see this information in the dialog. Low mode basically means that no check is made and macros will load and run automatically.
The bottom line? Low mode means that you have no protection against an incoming macro virus. You should at least run in Medium mode so that when you open a document containing code, the code signature can be checked and if it's borken, you'll have a dialog loaded where you can make a decision on whether to allow that code to be opened.
A good article that explains further about the security options is at http://msdn.microsoft.com/library/default.asp?url=/library/en-us/stagsdk/html/stconSecurityMatrix_HV01082171.asp. While this article title deals with SmartTags, the information in the article lays out a nice table of the security options and what they mean.
Next up? Self Cert options
