Answer:
Insider
Step-by-step explanation:
An insider security breach or threat is the breach that originates within an organization due to some of it's own employees who have access to the confidential information of the organization. It can include both current or former employees, interns or anyone else who have access to the critical systems of the company.
In the case mentioned in the question, the employees that are involved in the breach are current employees of the same company so this type of breach will be termed as an insider security breach.