MS Word 97 problems

Is there a new virus out there that is causing MS Office 97, MS Word to act crazy? On some files received as attachments to emails when opened in MS Word take on strange characteristics. The first few paragraphs seem OK but then the document enlarges text to a gigantic size, expanding the number of pages as well. Because of this, a four page document turns into a 1200 page document that is unreadable. I am interested in knowing if anyone else out there knows what I am talking about and if thereis a fix for this. It sounds like a virus and I have tried to run virus checks. They all seem fine. I checked with the office that originated the problem file and they have no problems reading it.