A Chinese-speaking advanced persistent threat (APT) actor has been linked to a new custom backdoor called TinyRCT as part of cyber attacks aimed at government entities and critical infrastructure in Southeast Asia.
The activity, particularly aimed at state-owned enterprises in the energy and government sectors, has been attributed to a threat actor called CL-STA-1062, which Palo Alto Networks Unit 42 said shares overlaps with UAT-7237, a hacking group that was first flagged by Cisco Talos in August 2025 in relation to a campaign directed against web infrastructure entities in Taiwan.
Unit 42 said it also observed CL-STA-1062 campaigns in prior operations targeting strategic sectors in East Asia since March 2022, suggesting a broader but sustained focus in the region.
"From a technical standpoint, the attackers behind CL-STA-1062 rely on a hybrid toolkit," Unit 42 said in a technical report. "While they frequently use common open-source tools such as SoftEther VPN, Mimikatz, and VNT, they have recently introduced TinyRCT, a bespoke, previously undocumented backdoor."
TinyRCT is equipped to run arbitrary commands, enumerate files and exfiltrate them, capture the device's screen, and delete itself from the compromised host.
