The Russia-linked cyber espionage group tracked as APT28 and Fancy Bear has started delivering malware to targeted users by leveraging a recently disclosed technique involving Microsoft Office documents and a Windows feature called Dynamic Data Exchange (DDE).
Researchers at McAfee noticed the use of the DDE technique while analyzing a campaign that involved blank documents whose name referenced the recent terrorist attack in New York City.
Researchers warned recently that DDE, a protocol designed for data exchanges between Windows applications, could be used by hackers as a substitute for macros in attacks involving malicious documents. Shortly after, security firms reported seeing attacks leveraging DDE to deliver malware, including Locky ransomware.
Microsoft pointed out that DDE, which has been replaced with Object Linking and Embedding (OLE), is a legitimate feature. The company has yet to make any changes that would prevent attacks, but mitigations included in Windows do provide protection, and users are shown two warnings before the malicious content is executed.
In the APT28 attacks spotted by McAfee, cyberspies used the document referencing the New York City attack to deliver a first-stage malware tracked as Seduploader. The malware, typically used by the threat actor as a reconnaissance tool, is downloaded from a remote server using PowerShell commands.
Based on the analysis of the malware and command and control (C&C) domains used in the attack, researchers determined that the campaign involving DDE started on October 25.
The attack using the New York City incident as lure appears to be part of a campaign that also involved documents referencing Saber Guardian, a multinational military exercise conducted by the U.S. Army in Eastern Europe in an effort to deter an invasion (by Russia) into NATO territory.
Another recent APT28 attack leveraged a document describing CyCon U.S., a conference organized by the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) in collaboration with the Army Cyber Institute at West Point. However, the CyCon attack relied on a malicious VBA script and it did not involve DDE.
“Given the publicity the Cy Con U.S campaign received in the press, it is possible APT28 actors moved away from using the VBA script employed in past actions and chose to incorporate the DDE technique to bypass network defenses,” McAfee researchers said in a blog post.
“[The] use of recent domestic events and a prominent US military exercise focused on deterring Russian aggression highlight APT28’s ability and interest in exploiting geopolitical events for their operations,” they added.