Security Engineer (ICS / OT Security & Architecture)

Job Description

About the Role: We are seeking a skilled and passionate Security Engineer specializing in Operational Technology (OT) and Industrial Control Systems (ICS). In this role, you will lead the security risk assessments, audits (SRAA), and architectural hardening (such as DMZ implementation) for our wastewater treatment control systems (SCADA/PLC). You will bridge the gap between IT and OT to safeguard our critical infrastructure against cyber threats and ensure regulatory compliance. Responsibilities: • SRAA & Compliance: Conduct comprehensive Security Risk Assessment and Audit (SRAA) on both hardware (PLCs, HMIs, network switches) and software (SCADA platforms, databases) levels against international standards (e.g., ISO 27001, IEC 62443). • Network Segmentation (DMZ): Design, review, and implement robust network segmentation architectures, specifically setting up Demilitarized Zones (DMZ), industrial firewalls, and data diodes to isolate the Wastewater Production Control Zone (DCS) from the Management Information Zone and DMZ. • Endpoint & Host Security: Deploy and manage antivirus software, Intrusion Detection/Prevention Systems (IDS/IPS), patch management, and vulnerability hardening across physical servers, NAS devices, and Virtual Machines (VMs). • OGCIO Compliance Management: Ensure the entire system infrastructure adheres strictly to Hong Kong OGCIO guidelines, including S17 (Baseline IT Security Policy), G3 (IT Security Guidelines), G54 (Incident Handling), and G51 (Security Risk Assessment & Audit). • Security Auditing & Penetration Testing: Act as the primary technical liaison for independent, certified cybersecurity firms to conduct comprehensive third-party security audits and pre-handover penetration testing. Document and remediate all identified vulnerabilities. • Data Integrity & Logging: Establish and monitor comprehensive audit trails, access controls, and logging functions to guarantee the Confidentiality, Integrity, and Availability (CIA triad) of time-series and ML result databases. Show More