Cyber security firms are specialised organisations that provide professional services and technology solutions to protect businesses, government agencies, and critical infrastructure from cyber threats. In Australia, cyber security firms support compliance with frameworks such as the Essential Eight, ISO 27001, APRA CPS 234, and the Security of Critical Infrastructure (SOCI) Act. These firms deliver services including risk assessments, penetration testing, security architecture design, incident response, managed detection and response (MDR), and governance advisory. Leading cyber security firms combine technical expertise with regulatory knowledge to address both operational and compliance requirements. They help organisations reduce attack surfaces, respond to ransomware threats, and strengthen resilience against nation-state and criminal actors. Engaging experienced cyber security firms enables businesses to access advanced skills, improve maturity, and maintain trust with customers and regulators.