Recently Adobe has announced there is a security exploit where hackers use a common Microsoft Word document to take advantage of a bug in Flash Player.
The hackers have been placing some nasty Flash based code within the Word documents, and even in some Excel spreadsheet files. When these files are opened, they sniff out important company information and pass it off to the hackers via the network. The document will link itself to multiple recipients within a corporation's email list. The most common discovery of the file was under the name of Disentangling Industrial Policy and Competition Policy, as to bait the unsuspecting to open it and have the hackers' plans reach fruition. The hackers would tailor the title of the email and respective document to anything related to their next victim's background.
The infected file extensions extend to even Adobe's own Acrobat PDFs, though there has not been any reports of malicious PDFs recorded as of yet. Some business owners have contemplated discontinuing use of Flash but cannot due to its deep roots in the world of computers. The companies must all live with stringent security checks on email attachments.