GoldenEyeDog Subgroup Linked to DigiCert Breach and Code-Signing Certificate Theft

Cybersecurity researchers have attributed the April 2026 DigiCert security incident to a threat activity cluster dubbed CylindricalCanine. Expel, which shared technical details of the event, described the threat actor as a sub-group of GoldenEyeDog (aka APT-Q-27, Dragon Breath, and Miuuti Group), a Chinese cybercrime group known for its targeting of the gambling and gaming sectors using