Information Systems Security Officer (ISSO) Associate

Definitive Innovative Solutions; Oakton (VA); On-site; USD 90,000 - 120,000; Full time

Job summary

Definitive Innovative Solutions (DIS) is seeking an Information Systems Security Officer (ISSO) Associate to support federal cybersecurity operations. You will lead RMF A&A activities, manage vulnerabilities, and maintain security postures for mission-critical systems, reporting to CISO/AO as needed.

The role requires TS/SCI clearance, strong NIST knowledge, and collaboration with ISSM, ISO, SCA, and AO. Initial in-office training is five days per week for ~two months, with potential telework up

Qualifications

• Bachelor's degree; Associate's degree with 2+ years experience OR 4+ years relevant experience.
• IAT Level II Certification.
• DoD Top Secret Clearance is required.

Responsibilities

• Provide oversight for assigned network to ensure compliance with STIGs and IAVM.
• Onsite five days a week during initial training (approx. two months); telework up to one day per week thereafter.
• Lead RMF A&A efforts and coordinate with ISSM, ISO, SCA and AO.
• Provide POA&M support and remediation coordination.
• Perform ConMon reviews and assist incident response activities.

Skills

TS/SCI Clearance

RMF/A&A

NIST SP 800-53

A&A packages (eMASS/Xacta)

POA&M & ConMon

Incident Response

Vulnerability Management

Security Tools (ACAS, Nessus)

Microsoft Office Proficiency

Education

Bachelor's degree

Associate degree with 2+ years experience or 4+ years experience

Tools

eMASS/Xacta

Splunk

Job description

Job Title: Information Systems Security Officer (ISSO) Associate

Location: Oakton, VA

Clearance: TS/SCI

Position Summary

Definitive Innovative Solutions (DIS) is a growing federal government contracting company seeking an Information Systems Security Officer (ISSO) Associate to support federal cybersecurity operations by ensuring compliance with federal security requirements, leading Risk Management Framework (RMF) and Authorization to Operate (ATO) activities, managing vulnerabilities, and maintaining the security posture of mission-critical information systems.

Duties and Responsibilities

• Provide oversight for the assigned network(s) by working with operation staff to ensure compliance per STIGs and IAVM.
• This role requires being onsite five days a week during the initial training period of approximately two months. Telework may then be authorized up to one day per week.
• Ensuring that Stakeholders adhere to Federal Information Assurance policies and procedures to acquire and maintain an Information System's Authority to Operate (ATO) under The Federal Information Security Management Act (FISMA) of 2002.
• Lead RMF A&A efforts including but not limited to: activities within the A&A cycle and ISSO functions, work directly with ISSM, ISO, SCA, and AO, work with engineering and operations support staff to secure systems and ensure compliance, and provide oversight for existing and new POAMs.
• Provide POA&M support by advising CISO/AO of changes and assisting in the coordination of efforts to remediate deficiencies and vulnerabilities.
• Performing ConMon reviews for daily, weekly, monthly, and quarterly checks. (Primarily completed through Splunk. Small number of manual/administrative checks).
• Assist with Incident Response (IR) activities by verifying sanitation procedures are followed prior to submitting the CART Case to the CISO for closure.
• Work with the Security Tools Team to identify Critical / High vulnerabilities for remediation and report network security posture at weekly CISO/AO meetings.
• Create, maintain, and enforce overarching policy documents to ensure continuity and compliance within the organization.
• Other duties as assigned.

Minimum Qualifications:

• Bachelor's degree
• Can be substituted for Associate's degree with 2+ years relevant experience OR 4+ years relevant experience
• IAT Level II Certification minimum
• DoD Top Secret Clearance is required

Knowledge, Skills and Abilities

• Experience with NIST SP 800-37, 800-137, 800-53 rev 4/5, 800-39, 800-171 and 800-171A for self-assessments; NIST 800-100, NIST 800-18.
• Familiar with creating Assessment and Authorization (A&A) packages in eMASS and/or Xacta and applying security categorization per the NIST FIPS 199 and NIST SP 800-60.
• Experience in performing and assessing Security and Privacy Controls per NIST 800-53 rev 4/5 and NIST 800-53a guidelines.
• Experience with systems engineering design and development toward a "baked-in" security design using Information Assurance best practices.
• Understanding of vulnerability and scanning tools such as Assured Compliance Assessment Solution (ACAS) and well-versed in interpreting risk posture resulting from assessment reports.
• Knowledge of vulnerability management, risk management, and project management, proficient with Microsoft products - Word, Excel, PowerPoint.
• Experience with Tenable's Nessus and/or Security Center, or Network Mapper is a plus.
• Risk assessment experience, especially with NIST SP 800-53 Threat identification, system security categorization, gap analysis, and compliance reporting.
• Must be able to validate security patches as they align with NIST guidelines, client policies and procedures, and OMB Mandates.
• Experience with creating or maintaining security artifacts as part of the ATO package including but not limited to; System Security Plans (SSP), Contingency Plans (CP), Disaster Recovery Plans (DRP), Plans of Action, and Milestone (POA&M), Incident Response (IR), and other security documentation.

Why Join DIS

Our culture is the heartbeat of our success. We believe that innovation doesn't just happen, it's cultivated through curiosity, collaboration, and a shared commitment to excellence. Our team is made up of passionate professionals who thrive in a dynamic environment where ideas are valued, creativity is encouraged, and growth is a shared journey.

Innovation at the Core

We foster a culture where innovation is not just a buzzword, it's a mindset. From daily stand-ups to strategic brainstorming sessions, we create space for experimentation and bold thinking. Our teams are empowered to challenge the status quo, explore emerging technologies, and develop solutions that push boundaries and deliver real impact for our clients.

People-First Philosophy

We invest in our people because we know they are our greatest asset. Through continuous learning opportunities, mentorship programs, and cross-functional collaboration, we help our team members grow both personally and professionally. We celebrate diverse perspectives and believe that the best ideas come from inclusive, empowered teams.

Agility and Ownership

Our culture embraces agility and accountability. We encourage initiative, reward problem-solving, and support a fail-fast, learn-faster approach. Every team member is trusted to take ownership of their work and contribute meaningfully to our mission.

Collaboration Without Borders

Whether remote or in-person, we maintain a strong sense of connection and community. We use modern tools to collaborate seamlessly across teams and time zones, ensuring that innovation and communication flow freely.

Definitive Innovativ e Solutions, LLC is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, protected veteran status, or any other characteristic protected by applicable federal, state, or local law.

Definitive Innovative Solutions, LLC will not discharge or in any other manner discriminate against employees or applicants because they have inquired about, discussed, or disclosed their own pay or the pay of another.