A client has approached you with a penetration test requirements. They are concerned with the possibility of external threat, and have invested considerable resources in protecting their Internet…

A client has approached you with a penetration test requirements. They are concerned with the possibility of external threat, and have invested considerable resources in protecting their Internet exposure. However, their main concern is the possibility of an employee elevating his/her privileges and gaining access to information outside of their respective department. What kind of penetration test would you recommend that would best address the client's concern?