Z​/OS UNIX System Services; USS Security Engineer

Enterprise Technology & Services

Enterprise Technology & Services (ETS) delivers shared technology services that support all business applications and over 3,000 production systems globally. ETS enables the full software development lifecycle—from development and testing to release engineering, monitoring, and operational support.

The Enterprise Z Security team is responsible for engineering and operating IBM Z mainframe authentication and authorization services. This position will be a member of the Enterprise Z Security team and responsible for design, implementation and monitoring security controls for z/OS UNIX System Services, ensuring that USS identity and permissions are properly integrated with mainframe security controls (RACF / Top Secret) and aligned to least privilege, auditability, and operational resilience.

The USS Security Engineer is responsible for securing and administering z/OS UNIX System Services (USS) environments on the mainframe. This role focuses on enforcing least privilege, protecting privileged access, and ensuring alignment between UNIX permissions, ESM controls (RACF/TSS), and enterprise security standards. The engineer will partner closely with Enterprise Z security architect, system programmers, middleware teams, and audit/compliance stakeholders to maintain a secure and compliant USS platform.

• Administer and manage USS identities, including UIDs, GIDs, OMVS segments, and service/shared IDs based on policy.
• Enforce naming standards, ownership traceability, and lifecycle controls for USS users and services.
• Manage and audit POSIX permissions, ownership, and execution rights across critical USS file systems.
• Control and monitor privileged access, including UID(0), setuid/setgid programs, and elevated authorities.
• Administer USS related ESM controls (RACF/TSS), including UNIXPRIV, FACILITY resources, and STARTED task identities.
• Secure USS configuration files, shell environments, PATH settings, and file system mount options.
• Monitor USS security events, logs, and audit records.
• Support production issues, security incidents, and access related investigations.
• Develop and maintain USS security standards, procedures, and documentation.

• Bachelor’s degree and 5+ years of experience with mainframe and z/OS UNIX System Services.
• Strong hands‑on experience securing USS environments.
• Proven experience administering RACF or equivalent ESM for USS.
• Solid understanding of:
  • UIDs, GIDs, OMVS segments, and service IDs.
  • POSIX permissions, ownership, and execution controls.
  • USS related security controls, including:
    • UNIXPRIV class.
    • FACILITY class resources impacting OMVS.
    • STARTED task identities for USS services.
  • Working knowledge of zFS/HFS file systems, mount options, and USS SMF/audit logging.
  • Strong understanding of least privilege and separation of duties principles.

• Experience with PKI, digital certificates, Kerberos, SSL/TLS, SSH, or OpenSSL.
• Exposure to systems programming concepts (e.g., SMP/E, SYS1 datasets, Assembler).
• Understanding of mainframe networking concepts.
• Experience supporting or securing middleware technologies (e.g., MQ).

Morgan Stanley offers attractive and comprehensive employee benefits and perks, including opportunities for growth and support across the organization.

Expected base pay rates for the role will be between $95,000 and $135,000 per year at the commencement of employment.

The total compensation package may also include commission earnings, incentive compensation, discretionary bonuses, other short and long-term incentive packages, and other Morgan Stanley sponsored benefit programs.

Morgan Stanley is an equal opportunity employer committed to building and maintaining a workforce that is diverse in experience and background. Our recruiting efforts reflect our strong commitment to a culture of inclusion, where individuals are hired, developed, and advanced based on their skills and talents.

Our workforce reflects a broad cross-section of the global communities in which we operate, bringing a variety of backgrounds, talents, perspectives, and experiences.

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