The scenario described involves a violation of the principle of confidentiality as defined in The IIA's Code of Ethics. The internal auditor misused information obtained during the course of an audit (salary data of colleagues) for personal gain (requesting a salary raise). This breaches the ethical principle of confidentiality, which mandates that auditors respect the value and ownership of information they receive and do not disclose information without appropriate authority unless there is a legal or professional obligation to do so.References:
The IIA's Code of Ethics on Confidentiality.