In an internal security audit, the white hat hacker gains control over a user account and attempts to acquire access to another account's confidential files and information. How can he achieve this?

Privilege escalation is the technique of leveraging an existing foothold to gain access to resources, data, or permissions beyond what the current account is authorized for. In this scenario, the attacker uses one compromised account to move laterally or vertically and access another account's confidential files. This is a core attack phase following initial compromise.

Shoulder-surfing is a physical observation technique used to steal credentials or sensitive information by watching someone's screen or keyboard, not a method for accessing files programmatically after account compromise.

Hacking Active Directory is a specific sub-technique targeting directory services infrastructure and is too narrow - it does not describe the general act of accessing another account's files.

Port scanning is a reconnaissance technique used to discover open network ports and services on a target system, not a method for accessing another user's files.