Information security is the most critical function when initiating the removal of system access for terminated employees, as it is responsible for ensuring that the access rights of the employees are revoked in a timely and effective manner, and that the security of the organization’s data and systems is maintained. Information security should coordinate with other functions, such as HR, legal, and help desk, to implement the access removal process, but it is the primary function that has the authority and capability to disable or delete the access credentials of the terminated employees. The other options are not as critical as information security, as they may have different roles or responsibilities in the access removal process, or they may not have direct access to the systems or tools that control the access rights of the employees. References =

CISM Review Manual 15th Edition, page 114: “Information security is responsible for ensuring that access rights are revoked in a timely and effective manner.”

SOC 2 Controls: Access Removal for Terminated or Transferred Users, snippets: “Systems access that is no longer required for terminated or transferred users is removed within one business day. For terminated employees, access to key IT systems is revoked in a timely manner. A termination checklist and ticket are completed, and access is revoked for employees as a component of the employee termination process.”

IT Involvement in Employee Termination, A Checklist, snippets: “Disable all network access. If your company uses a master access list of active passwords, tell the system to deny any passcodes associated with the user being terminated. If your system doesn’t have a deny function, delete the user and their associated passwords. Monitor employee access.”

Human resources (HR) is the most critical function when initiating the removal of system access for terminated employees because it is responsible for notifying the relevant parties, such as information security, help desk, and legal, of the employee’s termination status and date. HR also ensures that the employee’s exit process is completed and documented, and that the employee returns any company-owned devices or assets. HR also coordinates with the employee’s manager and team to ensure a smooth transition of work and responsibilities.