China-linked APT UNC3886 targets Singapore telcos

China-linked APT UNC3886 conducted a deliberate, targeted espionage campaign against all four major Singapore telcos beginning in July 2025, leveraging a zero-day to bypass defenses, deploy rootkits and passive backdoors, and exfiltrate network-related data; Singapore's CSA and IMDA led Operation CYBER GUARDIAN with telcos to contain the intrusion, limit attacker movement, remediate weaknesses, and enhance monitoring, with no large-scale data theft or service disruption reported so far.