On-Site Junior Security Engineer: Vulnerability & RMF/ATO

Leidos LLC; Plyers Mill Estates (MD); On-site; USD 70,000 - 126,000; Full time

Job summary

Leidos seeks a Junior Security Engineer to support day-to-day security activities across enterprise and isolated environments. This on-site role involves vulnerability management, security monitoring, RMF/ATO activities and continuous security improvements.

You will collaborate with senior security personnel, system admins and engineers, gaining hands-on experience across DISA STIGs, SIEMs like Splunk and security tooling to maintain a strong security posture.

Qualifications

• Experience handling security requirements across front, middle, and back end components.
• Experience with Windows Server 2016/2019, Active Directory, IIS, DNS, DHCP, Exchange.
• Experience implementing security controls on common network services across distributed sites.
• Experience with networking tech and security assessment incl. STIGs.
• Experience with malware monitoring and tools like Splunk, ACAS; strong TCP/IP and encryption knowledge.

Responsibilities

• Perform day-to-day security activities under supervision and resolve blockers.
• Support vulnerability management from identification through closure with documentation.
• Perform vulnerability scanning and analysis using ACAS/Nessus or equivalent.
• Collaborate with Windows/Linux/Network teams for remediation and hardening.
• Implement and validate DISA STIGs and security baselines across infrastructure.
• Conduct security reviews, log reviews, and continuous monitoring activities.
• Assist RMF/ATO activities with security documentation and BoEs.
• Review changes for potential security impact and document findings.

Skills

Vulnerability management

Security monitoring

Windows/Linux

RMF/ATO

SIEM (Splunk)

Security+ or equivalent

Education

Bachelor's degree

Tools

ACAS

Tenable/Nessus

Splunk

McAfee HBSS

AD/ IIS / DNS basics

Job description

Leidos seeks a Junior Security Engineer to support day-to-day security activities across enterprise and isolated environments. This on-site role involves vulnerability management, security monitoring, RMF/ATO activities and continuous security improvements.

You will collaborate with senior security personnel, system admins and engineers, gaining hands-on experience across DISA STIGs, SIEMs like Splunk and security tooling to maintain a strong security posture.