A sophisticated cyber espionage campaign, linked to Chinese state-aligned threat actors, has been targeting organizations across 15 countries, primarily in Europe, the Middle East, and Asia. Trend Micro’s analysis shows that this campaign, which began in November 2023, exploits weak passwords and multi-factor authentication (MFA) bypass techniques to gain access to networks. The attackers have primarily impacted organizations in the manufacturing, energy, finance, and education sectors.
The method of attack involves brute-forcing administrative credentials or bypassing certificate-based MFA to infiltrate Check Point firewall VPNs.
Once the attackers have gained access, they deploy an updated version of the Shadowpad malware, a modular backdoor previously linked to Chinese advanced persistent threat (APT) groups. This version of Shadowpad is equipped with advanced anti-analysis techniques to avoid detection. It uses the Process Environment Block (PEB) to check for debugger flags and employs CPU cycle measurements to identify potential sandbox environments. Additionally, the malware utilizes DNS-over-HTTPS for communication with its command-and-control (C2) servers, making it even more challenging to detect using network-based methods.
After establishing persistence, the attackers deploy a custom ransomware strain that encrypts files using AES-256 encryption, with the AES keys wrapped in RSA-2048 encryption. The encrypted files are appended with a .locked extension, and ransom notes, resembling those of the Kodex Evil Extractor ransomware, direct victims to a Tor payment portal. However, forensic analysis has shown that no payments have been made, indicating that the encryption phase might serve as a distraction while the attackers exfiltrate sensitive data. The attackers used tools like CQHashDumpv2 and WmiExec to extract Active Directory credentials and move laterally across the network, further compromising organizational systems.
The infrastructure used by the attackers has shown overlaps with the Chinese APT group Teleboyi, which has been linked to the PlugX malware, suggesting potential collaboration between the two groups. Trend Micro has urged organizations to audit their firewall configurations, enforce strong MFA practices, and monitor for signs of Shadowpad’s registry-based payload storage. It’s critical for organizations to stay vigilant against this evolving threat, as the cybercriminals behind this campaign continue to enhance their capabilities and tactics.
