What is the main concern for an IS auditor when a service provider outsources work involving confidential information?

When a service provider is tasked with handling confidential information, the primary concern for an IS auditor centers around the potential compromise of that confidentiality. This concern arises because outsourcing introduces third parties into the data handling process, increasing the risk that sensitive information could be inadvertently exposed, misused, or accessed by unauthorized individuals.

The nature of outsourcing means that the original organization must rely on the service provider to implement robust security measures, maintain data integrity, and comply with privacy regulations. The auditor's role is to ensure there are adequate safeguards in place to protect the confidentiality of the information throughout its lifecycle. If these measures are weak or ineffective, the risk of data breaches or leaks escalates, jeopardizing not just the organization’s data but also its reputation and compliance with regulations.

The other options, while relevant to various aspects of the outsourcing relationship, do not directly address the most pressing risk when confidential information is involved. Issues like contractual obligations, financial stability, and potential legal repercussions are indeed important, but they serve as secondary concerns compared to the fundamental obligation to secure sensitive data.