Kaspersky researchers have uncovered an advanced cyberespionage campaign targeting government and military organizations in Vietnam.
They believe this campaign was conducted by a group related to Cycldek, a Chinese-speaking threat group that has been active since at least 2013. New tactics seen in this campaign represent "a major advancement in terms of sophistication," Kaspersky says in a statement on the findings.
A penchance for technique and methodology sharing is common among Chinese-speaking threat actors. When researchers saw attackers using a well-known tactic, "the DLL side-loading triad," in this newly discovered campiagn, they immediately took notice.
DLL, or dynamic-link libraries, are pieces of code meant to be used by other programs on a computer. In this campaign, the DLL side-loading infection chain executes a shellcode that decrypts a remote access Trojan that Kaspersky calls FoundCore. This gives attackers full control over an infected device.
"More interesting, however, was the method used to protect the malicious code from analysis; a method that signals a major advancement in sophistication for attackers in this region," Kaspersky explains in a release. "The headers (the destination and source for the code) for the final payload were completely stripped away, and the few that remained contained incoherent values. In doing this, the attackers make it significantly more difficult for researchers to reverse engineer the malware for analysis."
The components of this particular infection chain are tightly coupled, meaning single pieces can be difficult, or impossible, to analyze in isolation. This can prevent analysts from gaining a full picture of malicious activity.
Analysis suggests this activity was conducted by a group related to Cycldek, also known as Goblin Panda and Conimes. Cycldek has been using a variety of tools, tactics, and procedures in attacks against government agencies in Vietnam, Laos, and Thailand since 2018. Last year, Kaspersky research revealed previously unknown information suggesting its operators had a foothold in the networks of several high-profile targets in these countries.
More detail on today's research is included in this press release.