Automated version control systems are the best method to maintain an audit trail of changes made to the source code of a program. They automatically track and manage changes to the source code over time, allowing you to see what changes were made, when they were made, and who made them1. This provides a clear and detailed audit trail that can be invaluable for debugging, understanding the evolution of the code, and ensuring accountability23.

The best source of information for assessing the effectiveness of IT process monitoring is performance data.
Performance data is a type of information that measures and reports on the results or outcomes of IT processes, such as availability, reliability, throughput, response time, or error rate. Performance data can help assess the effectiveness of IT process monitoring by providing quantitative and qualitative indicators of whether IT processes are meeting their objectives, standards, or expectations. The other options are not as good as performance data in assessing the effectiveness of IT process monitoring, as they do not provide direct or objective evidence of IT process results or outcomes. Real-time audit software is a type of tool that can help automate and facilitate audit activities, such as data collection, analysis, or reporting, but it does not provide information on IT process performance. Quality assurance (QA) reviews are a type of activity that can help evaluate and improve the quality of IT processes, products, or services, but they do not provide information on IT process performance. Participative management techniques are a type of method that can help involve and motivate IT staff in decision-making and problem-solving processes, but they do not provide information on IT process performance. References: CISA Review Manual (Digital Version), Chapter 3, Section 3.3

Machine shredding is the process of using a shredding machine to physically destroy the media and make the data unrecoverable. This is more effective than software formatting, which only erases the data logically and may leave traces that can be recovered by special tools1. Encrypting and destroying keys may prevent unauthorized access to the data, but it does not erase the data from the media. Wiping and rewriting three times is unnecessary and may reduce the lifespan of the media, especially for solid state drives2. Machine shredding is also recommended by various security standards and guidelines for media disposal345.

The IS auditor should notify audit management of the finding first, as this is a significant issue that may affect the audit scope and objectives. The IS auditor should not notify law enforcement or require the third party to notify customers without consulting audit management first. The audit report with a significant finding should be issued after the audit is completed and the findings are validated. References: ISACA, CISA Review Manual, 27th Edition, 2018, page 247