Researchers from Sophos have discovered that an Advanced Persistent Threat (APT) group, known as Dragon Breath or APT-Q-27 and Golden Eye, has employed a new DLL sideloading technique to distribute malware. The attack includes a clean application that functions as a malicious loader and an encrypted payload. In the latest campaigns, a first-stage clean application sideloads a second clean application, which then sideloads the malicious loader DLL that executes the final payload. This technique adds complexity and layers to the execution of classic DLL sideloading.
Dragon Breath is believed to be focused on organizations in the online gambling industry and their customers, with most victims being Chinese-speaking Windows users. The group has been active since 2020 and uses Telegram to distribute the malware. Targets have been observed in the Philippines, Japan, Taiwan, Singapore, Hong Kong, and China. The researchers discovered a website that claims to deliver Chinese-language versions of the Telegram application for Android, iOS, and Windows, which they suspect is the site from which the affected user downloaded the package that caused the infection.
The malicious code maintains persistence by creating a shortcut file in the user’s startup directory, and the researchers have observed more first-stage variations using LetsVPN and WhatsApp installers. The payloads support common backdoor capabilities such as downloading and executing files, running arbitrary commands, clearing event logs, and extracting and setting clipboard content. The malware is also capable of stealing cryptocurrency from the MetaMask crypto (Ethereum) wallet extension for Google Chrome.
The researchers conclude that DLL sideloading, first identified in Windows products in 2010, continues to be an effective tactic for threat actors. This technique employed by the Dragon Breath group, targeting a user sector that has traditionally been less scrutinized by security researchers, represents the continued vitality of this approach.
