A family of Microsoft word processing software products for creating web, email, and print documents.
The other responses you've gotten show that knowledgeable users of Word don't recognize "IMG PDF" as anything they've ever seen (and I agree). That's why you're being asked for a screenshot.
On a guess, if the object appears in what should be a blank document when you open Word without specifying an existing document, then it's probably coming from your Normal.dotm template. You can edit that template to remove the object, or delete the template and let Word create a new one. For details, see http://wordfaqs.ssbarnhill.com/BlankDocNotBlank.htm.