Russian Hackers using New York Terror Attack to Lure Victims into Lure them into clicking on malicious documents, which eventually infects their systems with malware. DDE attack technique has been found leveraging by an Advanced Persistent Threat (APT) hacking group APT28, which is well known as Fancy Bear and is widely believed to be backed by the Russian government. Most antivirus solutions don’t flag any warning or block the documents with DDE fields. Microsoft does not consider the vulnerability as a security issue and has already denied to patch it.
Source: https://thehackernews.com/2017/11/apt28-office-dde-malware.html