Vulnerability Management Specialist (Microsoft Sentinel)

About a23

a23 is an Australian owned Systems Integrator headquartered in Canberra. We provide specialist ICT services across diverse technologies and are recognised as a valued strategic partner for Government and private sector organisations. a23 has grown to become a prominent strategic partner, focused on servicing the needs of small to medium-sized agencies to deliver quality outcomes through expert people, great relationships, and fit-for-purpose technologies.

Why work for a23?

a23 is a well-established Australian technology company experiencing strong growth, fuelled by rising demand for our expertise in Cyber Security, Networking, Cloud, Data and AI, and Hybrid Cloud. We bring the agility and innovation of a start-up backed by the maturity, credibility, and delivery assurance of an established market leader.

Our teams deliver secure, scalable solution to government and enterprise client, blending deep technical capability with a client-first culture. Whether enabling AI-driven insights, transforming hybrid infrastructure, or securing mission-critical environments, a23 is trusted to deliver at a national scale.

We offer a collaborative and flexible working environment alongside a range of employee benefits such as an annual wellbeing allowance. For more information, see our Careers page at www.a23.com.au/our-careers/.About the role

The Role

a23 is seeking an experienced Vulnerability Management Specialist to support and continuously improve the customer's CTVM capability, with a particular focus on Microsoft Defender and the broader Microsoft security ecosystem. The role will support the effective use of existing Microsoft security capabilities to improve vulnerability and exposure visibility, analyse security data, investigate emerging threats, and work directly with system owners to reduce cyber risk. The successful candidate will partner closely with infrastructure, cloud, application, and cyber operations teams to improve security visibility and vulnerability detection coverage across endpoints, servers and other supported assets, improve remediation outcomes, enhance risk-based prioritisation, and support the Department's ongoing security uplift initiatives.

Key responsibilities

• Administer, configure and optimise Microsoft Defender security capabilities, with a particular focus on vulnerability management.

• Monitor and improve endpoint and server security visibility, including identifying coverage gaps, onboarding issues and other factors affecting vulnerability and exposure data.

• Conduct vulnerability assessments and analyse findings from Microsoft Defender, threat intelligence, security monitoring, manual validation and other available security data sources.

• Investigate emerging vulnerabilities, exploits and cyber threats to determine potential exposure and impact to PM&C systems.

• Drive vulnerability remediation activities by working directly with system owners, infrastructure teams and other technical stakeholders to implement patches, mitigations and compensating controls.

• Use Microsoft Defender vulnerability and exposure information to support risk-based prioritisation, including consideration of exploitability, threat intelligence, asset criticality and operational context.

• Develop and maintain dashboards, reports, metrics, queries and operational views to improve visibility of vulnerabilities, exposures, remediation activities and security posture.

• Work with other technical specialists, engineers and key stakeholders to ensure critical security patches, mitigations and monitoring controls are implemented in a timely manner.

• Support integration and effective use of vulnerability and security information across the Microsoft security ecosystem, including Microsoft Defender and Microsoft Sentinel where applicable.

• Contribute to continuous improvement initiatives that enhance the customer's vulnerability management, exposure management and broader cyber resilience capabilities.

About you

• 5+ years' demonstrated operational experience in cyber security vulnerability management, endpoint security, vulnerability assessment or security operations within a complex enterprise environment.

• Demonstrated hands-on experience administering, configuring and operationally using Microsoft Defender for Vulnerability Management, including investigation of endpoint security and vulnerability information.

• Experience using Microsoft Defender vulnerability management capabilities to identify vulnerabilities, assess exposure, prioritise remediation and monitor remediation outcomes.

• Strong understanding of the vulnerability management lifecycle, including asset visibility, vulnerability identification, validation, prioritisation, remediation, mitigation and risk acceptance.

• Experience analysing vulnerability, endpoint and threat data and translating technical findings into actionable, risk-based recommendations for system owners and technical teams.

• Experience identifying and resolving security visibility or coverage gaps, including endpoint/server onboarding, configuration and data quality issues.

• Experience developing dashboards, reports, metrics or operational security views to support vulnerability management and cyber security outcomes.

• Proven ability to engage with technical stakeholders and drive remediation outcomes across infrastructure, cloud, application and cyber security teams.

• Strong written and verbal communication skills, including the ability to explain technical vulnerabilities and cyber risk to both technical and non-technical audiences.

• NV1 minimum required for this role.