The best way to facilitate the legal process in the event of an incident is to preserve the chain of custody of the evidence. The chain of custody is a record of who handled, accessed, or modified the evidence, when, where, how, and why. The chain of custody helps to ensure the integrity, authenticity, and admissibility of the evidence in a court of law. The chain of custody also helps to prevent tampering, alteration, or loss of evidence that could compromise the investigation or the prosecution. References:
* CISAReview Manual (Digital Version)
* CISA Questions, Answers & Explanations Database

A mirror backup is a type of backup that creates an exact copy of the source data to the destination, without using any compression or encryption. A mirror backup is the best backup scheme to recommend given the need for a shorter restoration time in the event of a disruption, because it allows for the fastest and easiest recovery of data. A mirror backup does not store any previous versions of the files, so it only reflects the current state of the source data. Therefore, a mirror backup requires less storage space than a full backup, but more than an incremental or differential backup.
A differential backup is a type of backup that stores the changes made to the source data since the last full backup. A differential backup requires less storage space and time than a full backup, but more than an incremental backup. However, a differential backup also requires more time and resources to restore than a mirror or full backup, because it needs to combine the last full backup and the latest differential backup to recover the data.
A full backup is a type of backup that copies all the files and folders from the source data to the destination, regardless of whether they have changed or not. A full backup provides the most complete protection of data and the simplest recovery process, but it also requires the most storage space and time to perform. A full backup is usually done periodically, such as weekly or monthly, and followed by incremental or differential backups.
An incremental backup is a type of backup that stores the changes made to the source data since the last backup, whether it was a full or an incremental backup. An incremental backup requires the least storage space and time to perform, but it also requires the most time and resources to restore, because it needs to combine all the previous backups in chronological order to recover the data.

A network firewall is a device or software that monitors and controls the incoming and outgoing network traffic based on predefined rules. A network firewall can help reduce the risk of denial of service (DoS) attacks, which are attempts to overwhelm a system or network with excessive requests or traffic, by filtering or blocking unwanted or malicious packets. A SQL injection attack is a type of code injection attack that exploits a vulnerability in a web application's database query, by inserting malicious SQL statements into the input fields. A phishing attack is a type of social engineering attack that attempts to trick users into revealing sensitive information or installing malware, by sending fraudulent emails or messages that impersonate legitimate entities. An insider attack is a type of malicious activity that originates from within an organization, such as employees, contractors, or partners, who abuse their access privileges or credentials to compromise the confidentiality, integrity, or availability of information systems or data. A network firewall cannot prevent these types of attacks, as they rely on exploiting human or application weaknesses rather than network vulnerabilities.

The primary purpose of performing a parallel run of a new system is to validate the new system against its predecessor. A parallel run is a strategy for system changeover where a new system slowly assumes the roles of the older system while both systems operate simultaneously. This allows for comparison of the results and outputs of both systems to ensure that the new system is working correctly and reliably. A parallel run can also help identify and resolve any errors, discrepancies, or inconsistencies in the new system before the old system is discontinued.
The other options are not the primary purpose of performing a parallel run of a new system. A. To train the end users and supporting staff on the new system. Training is an important part of system implementation, but it is not the main reason for doing a parallel run. Training can be done before, during, or after the parallel run, depending on the needs and preferences of the organization. B. To verify the new system provides required business functionality. Verifying the business functionality of the new system is part of user acceptance testing (UAT), which is a formal and structured process of testing whether the new system meets the specifications and expectations of the users and stakeholders. UAT is usually done before the parallel run, as a prerequisite for system changeover. C. To reduce the need for additional testing. Reducing the need for additional testing is not the primary purpose of performing a parallel run, but rather a possible benefit or outcome of doing so. A parallel run can help ensure that the new system is thoroughly tested and validated in a real-world environment, which may reduce the likelihood of encountering major issues or defects later on.
However, additional testing may still be needed after the parallel run, depending on the feedback and evaluation of the users and stakeholders.
References:
* ISACA, CISA Review Manual, 27th Edition, 2019, p. 2471
* IS

The first step when conducting an IT risk assessment is to identify assets to be protected, which include hardware, software, data, processes, people, and facilities that support the business objectives and operations of an organization. Identifying assets to be protected helps to establish the scope and boundaries of the risk assessment, as well as the value and criticality of each asset. Identifying potential threats, assessing vulnerabilities, and evaluating controls in place are subsequent steps in the risk assessment process that depend on the identification of assets to be protected. References: CISA Review Manual (Digital Version), Chapter 2: Governance & Management of IT, Section 2.3: IT Risk Management