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

Cybersecurity researchers have linked the April 2026 DigiCert security incident to a threat activity cluster known as CylindricalCanine. This cluster is a subgroup of GoldenEyeDog, a Chinese cybercrime group. GoldenEyeDog is known for targeting the gambling and gaming sectors. The incident involved the theft of a code-signing certificate. Researchers at Expel have shared technical details of the event. The breach is attributed to the actions of this subgroup of GoldenEyeDog.