Isaca CISA Actual Questions

The most helpful thing for an IS auditor when assessing the effectiveness of controls is the results of control testing, as this provides objective and reliable evidence of how well the controls are designed and operating in practice. A control self-assessment (CSA) is a technique that involves the participation of process owners and stakeholders in evaluating the effectiveness of controls, but it may not be as rigorous or independent as control testing. Interviews with management are useful for gaining an understanding of the control environment and culture, but they may not reflect the actual performance of controls. A control matrix is a tool that maps the controls to the objectives, risks, and requirements, but it does not measure the effectiveness of controls. References: CISA Review Manual (Digital Version), Chapter 1: Information Systems Auditing Process, Section 1.3: IT Audit Process

The best way to sanitize a hard disk for reuse to ensure the organization’s information cannot be accessed is data wiping. Data wiping is a process that overwrites the data on the hard disk with random or meaningless patterns, making it unrecoverable by any software or hardware methods. Data wiping can provide a high level of security and assurance that the organization’s information is permanently erased from the hard disk, and that it cannot be accessed by unauthorized parties or malicious actors.

Re-partitioning is not a way to sanitize a hard disk for reuse, but rather a way to organize the hard disk into different logical sections or volumes. Re-partitioning does not erase the data on the hard disk, but only changes the structure and allocation of the disk space. Re-partitioning may make the data inaccessible to the operating system, but not to other tools or methods that can scan or recover the data from the disk sectors.

Degaussing is a way to sanitize a hard disk for reuse, but only for magnetic hard disks, not solid state drives (SSDs). Degaussing is a process that exposes the hard disk to a strong magnetic field, which disrupts and destroys the magnetic alignment of the data on the disk platters. Degaussing can effectively erase the data on magnetic hard disks, but it can also damage or render unusable the electronic components of the hard disk, such as the read/write heads or circuit boards. Degaussing also does not work on SSDs, which store data using flash memory cells, not magnetic media.

Formatting is not a way to sanitize a hard disk for reuse, but rather a way to prepare the hard disk for use by an operating system. Formatting is a process that creates a file system on the hard disk, which defines how the data is stored and accessed on the disk. Formatting does not erase the data on the hard disk, but only deletes the file system metadata and marks the disk space as available for new data. Formatting may make the data invisible to the operating system, but not to other tools or methods that can restore or recover the data from the disk sectors.

References:

How to Wipe A Hard Drive for Reuse? Check the Quickest Way to Wipe A Hard Drive - EaseUS 1

HP PCs - Using Secure Erase or HP Disk Sanitizer 2

HOW to QUICKLY and PERMANENTLY SANITIZE ANY DRIVE (SSD, USB thumb drive …) 

 Sampling risk is the risk that the auditor’s conclusion based on a sample may be different from the conclusion that would be reached if the entire population was tested using the same audit procedure. Sampling risk can lead to either incorrect rejection or incorrect acceptance of the audit objective. The best way to minimize sampling risk is to perform statistical sampling. Statistical sampling is a method of selecting and evaluating a sample using probability theory and mathematical calculations. Statistical sampling allows auditors to measure and control the sampling risk by determining the appropriate sample size and selection method, and evaluating the results using confidence levels and precision intervals. Statistical sampling can also provide more objective and consistent results than judgmental sampling, which relies on the auditor’s professional judgment and experience.

References:

6: Sampling Risks: Definition, Example, and Explanation - Wikiaccounting

7: Sampling Risk in Audit | Sampling vs non sampling risk - Accountinguide

9: Audit sampling | ACCA Qualification | Students | ACCA Global

The best assurance of data integrity after file transfers is hash values. Hash values are unique strings that are generated by applying a mathematical function to the data. Hash values can be used to verify that the data has not been altered or corrupted during the transfer, as any change in the data would result in a different hash value. By comparing the hash values of the source and destination files, one can confirm that the data is identical and intact.

The other options are not as effective as hash values for ensuring data integrity after file transfers. Check digits are digits added to a number to detect errors in data entry or transmission, but they are not reliable for detecting intentional or complex modifications of the data. Monetary unit sampling is a statistical sampling technique used for auditing financial statements, but it is not applicable for verifying data integrity after file transfers. Reasonableness check is a validation method that checks whether the data falls within an expected range or format, but it does not guarantee that the data is accurate or consistent with the source.

References:

5: On Windows, how to check that data is unchanged after copying? - Super User

6: Data integrity | Cloud Storage Transfer Service Documentation | Google Cloud

7: Checking File Integrity - HECC Knowledge Base

8: How to setup File Transfer Integrity Checks - Progress.com