USBs are back: Rare, advanced threat campaign targets users

Kaspersky experts have uncovered a rare, wide-scale advanced persistent threat (APT) campaign against users that was first detected in Southeast Asia. Kaspersky identified approximately 1,500 victims, some of which were government entities. Initial infection occurs via spear-phishing emails containing a malicious Word document; once downloaded on one system, the malware can then spread to other hosts through removable USB drives.

APT campaigns are, by nature, highly targeted. Often, no more than a few dozen users are targeted, often with surgical-like precision. However, recently, Kaspersky uncovered a rare, widespread threat campaign with a rarely used, yet still a movie-like attack vector. Once downloaded on a system, the malware attempts to infect other hosts by spreading through removable USB drives. If a drive is found, the malware creates hidden directories on the drive, where it then moves all of the victim’s files, along with the malicious executables.

This cluster of activity — dubbed LuminousMoth — has been conducting cyber-espionage attacks against government entities since at least October 2020. While initially focusing their attention on Myanmar, the attackers have since shifted their focus to the Philippines. The attackers typically gain an initial foothold in the system through

a spear-phishing email with a Dropbox download link. Once clicked, this link downloads a RAR archive disguised as a Word document that contains the malicious payload.

Kaspersky experts attribute LuminousMoth to the HoneyMyte threat group, a well-known, longstanding, Chinese-speaking threat actor, with medium to high confidence. HoneyMyte is primarily interested in gathering geopolitical and economic intelligence in Asia and Africa.

“This new cluster of activity might once again point to a trend we’ve been witnessing over the course of this year: Chinese-speaking threat actors retooling and producing new and unknown malware implants,” said Mark Lechtik, senior security researcher with the Global Research and Analysis Team (GReAT).

To stay safe from advanced threat campaigns like LuminousMoth, Kaspersky experts recommend:

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Providing your staff with basic cybersecurity hygiene training, as many targeted attacks start with phishing or other social engineering techniques. •

Carrying out a cybersecurity audit of your networks and remediating any weaknesses discovered in the perimeter or inside the network. •

Installing anti-APT and EDR solutions, enabling threat discovery and detection, investigation and timely remediation of incidents capabilities.

All of the above is available within the Kaspersky Expert Security framework.

That along with proper endpoint protection, dedicated services can help against high-profile attacks. The Kaspersky Managed Detection and Response service can help identify and stop attacks in their early stages, before the attackers achieve their goals.