Microsoft Fancy Bear, the advanced hacking group researchers say is tied to the Russian government, is actively exploiting a newly revived technique that gives attackers a stealthy means of infecting computers using Microsoft Office documents, security researchers said this week. Fancy Bear is one of two Russian-sponsored hacking outfits researchers say breached Democratic National Committee networks ahead of last year's presidential election. The group was recently caught sending a Word document that abuses a feature known as Dynamic Data Exchange. DDE allows a file to execute code stored in another file and allows applications to send updates as new data becomes available. In a blog post published Tuesday , Trend Micro researchers said Fancy Bear was sending a document titled IsisAttackInNewYork.docx that abused the DDE feature. Once opened, the file connects to a control server to download a first-stage of piece of malware called Seduploader and installs it on a ...