I don't think viruses can be carried in .txt or .rtf . They can in .doc because microsoft will execute code for you, even if you don't ask it to.
People, when you get an email from Google, eBay, Yahoo, or whatever, look at the link properties (hovering the mouse over the link and look at the status bar, or right-click). If it doesn't say "yahoo.com" or "https://ebay.com" in there, it's probably not real. Also, don't even bother using the link to get to those sites. You can get there just as easily by typing the site in the address bar.