Short Answer 
Insider threats are defined as individuals with authorized access who compromise an organization’s security. Evaluating potential threats requires assessing individuals’ access and employment status, highlighting Maria and Jin as notable risks, while monitoring Ron due to his connection to a DOD employee.
Step 1: Understand Insider Threat Definition
According to the National Insider Threat Task Force (NITTF), an insider threat is defined as individuals who have authorized access to an organization’s resources and use that access to compromise the organization’s security. Recognizing this definition is crucial to identifying individuals who may be a potential risk. Important aspects include:
- Authorized access to sensitive information.
- The ability to exploit that access.
- Relation or connection to individuals with security clearances.
Step 2: Evaluate Each Scenario
In order to determine which of the provided scenarios describes potential insider threats, each individual’s employment status and access to sensitive information must be assessed. The following evaluations need to be considered:
- Ron: Unemployed and married to a DOD employee with Secret eligibility; not an insider threat himself but could require monitoring.
- Susan: Works for a cleared defense contractor but lacks national security eligibility; thus, she is not a potential insider threat.
- Jin: A vendor without security clearance who frequently visits cleared facilities; may pose a risk due to unrestricted access.
- Maria: A project manager with Secret eligibility for a cleared contractor; she clearly meets the insider threat criteria.
Step 3: Identify Potential Insider Threats
Based on the evaluations, identify which individuals may pose a potential threat according to the NITTF definition. The following individuals should be noted:
- Maria – she has been granted Secret eligibility.
- Jin – even without eligibility, frequent visits may imply risk.
While Ron’s circumstances necessitate monitoring, he does not fit the definition of an insider threat. Thus, focus on individuals with direct access to classified information.