CISA Exam Dumps - Certified Information Systems Auditor

A demilitarized zone (DMZ) is a network segment that is separated from the internal network and the external network, such as the internet, by firewalls or other security devices. A DMZ provides an extra layer of security for the organization’s internal network by isolating the servers and services that need to be accessible to external users, such as a file server, from the rest of the network. A DMZ also prevents external users from accessing the internal network directly, as they have to go through two firewalls to reach it. Therefore, setting up a DMZ is an IS auditor’s best recommendation to protect anorganization from attacks when its file server needs to be accessible to external users12.

The other possible options are:

Enforce a secure tunnel connection: This means that the organization requires external users to establish a secure and encrypted connection, such as a virtual private network (VPN), to access its file server. This can provide some level of security and privacy for the data transmission, but it does not protect the file server or the internal network from attacks if the connection is compromised or if the external users are malicious. Therefore, enforcing asecuretunnel connection is not an IS auditor’s best recommendation to protect an organization from attacks when its file server needs to be accessible to external users3.

Enhance internal firewalls: This means that the organization improves the security and performance of its internal firewalls, which are devices that filter and control the network traffic between different segments of the network. This can provide some level of protection for the internal network from unauthorized or malicious access, but it does not protect the file server or the external network from attacks if the file server is exposed to the internet or if the external network is compromised. Therefore, enhancing internal firewalls is not an IS auditor’s best recommendation to protect an organization from attacks when its file server needs to be accessible to external users4.

Implement a secure protocol: This means that the organization uses a secure and standardized protocol, such as Secure File Transfer Protocol (SFTP) or Secure Shell (SSH), to transfer files between its file server and external users. This can provide some level of security and integrity for the data transmission, but it does not protect the file server or the internal network from attacks if the protocol is exploited or if the external users are malicious. Therefore, implementing a secure protocol is not an IS auditor’s best recommendation to protect an organization from attacks when its file server needs to be accessible to external users5. References: 1: What Is a DMZ Network and Why Would You Use It? | Fortinet 2: Demilitarised zone (DMZ) | Cyber.gov.au 3: What Is VPN Tunneling? | Fortinet 4: Firewall - Wikipedia 5: Secure Shell - Wikipedia

The first task that an IS auditor should complete during the preliminary planning phase of a database security review is to determine which databases will be in scope. The scope defines the boundaries and objectives of the audit, as well as the resources, time, and budget required. The IS auditor should identify the databases that are relevant to the audit based on factors such as their criticality, risk, complexity, size, type, location, and ownership. The IS auditor should also consider the regulatory, contractual, and organizational requirements that apply to the databases. By defining the scope clearly and accurately, the IS auditor can ensure that the audit is focused, feasible, and effective. References:

CISA Review Manual (Digital Version)

CISA Questions, Answers and Explanations Database

A digital signature is a specific type of e-signature that is backed by a digital certificate. A digital certificate is a document that contains the public key of a signer and is issued by a trusted third party called a certificate authority (CA). A digital signature provides proof of the identity of the signer and the integrity of the signed document.

A characteristic of a digital signature is that it is unique to the message. This means that a digital signature cannot be copied from one document to another without being detected as invalid. A digital signature is created by applying a mathematical function called a hashing algorithm to the document. A hashing algorithm produces a fixed-length output called a hash or digest from any input data. The hash is unique to the input data; any change in the input data will result in a different hash.

The signer then encrypts the hash with their private key (a secret key that only they know) to create the digital signature. The encrypted hash is attached to the document as the digital signature. The recipient of the document can verify the digital signature by decrypting it with the signer’s public key (a key that is publicly available and matches the private key) to obtain the hash. The recipient then applies the same hashing algorithm to the document to generate another hash. The recipient then compares the two hashes; if they match, it means that the document has not been altered and that the signer is authentic.

Therefore, a digital signature is unique to the message because it is derived from the hash of the message, which is unique to the message.

The charging method for IS resources is the way that the IS function allocates its costs to the users or business units that consume its services. The charging method can affect the behavior and incentives of the users and the IS function, as well as the efficiency and effectiveness of the IS resources. Therefore, choosing an appropriate charging method is an important decision for the IS function and its stakeholders.

One of the possible charging methods is to charge specific costs that can be tied back to specific usage. This means that the IS function tracks and measures the actual consumption of each user or business unit for each IS service, and charges them accordingly. For example, if a user uses 10 GB of storage space, 5 hours of CPU time, and 100 MB of network bandwidth, the IS function will charge them based on the unit costs of these resources. This charging method has the advantage of encouraging the most efficient use of IS resources, as it provides clear and accurate feedback to the users about their consumption and costs, and motivates them to optimize their usage and avoid waste or overuse. This charging method also aligns the interests of the IS function and the users, as both parties benefit from reducing costs and improving efficiency.

The other possible charging methods are:

Total utilization to achieve full operating capacity: This means that the IS function charges a fixed amount to each user or business unit based on their proportion of the total operating capacity of the IS resources. For example, if a user or business unit has 10% of the total computing power allocated to them, they will pay 10% of the total IS costs. This charging method has the disadvantage of discouraging efficient use of IS resources, as it does not reflect the actual consumption or usage of each user or business unit, and does not provide any incentive to reduce costs or improve efficiency. This charging method also creates a mismatch between the interests of the IS function and the users, as the IS function benefits from increasing costs and capacity, while the users bear the burden of paying for them.

Residual income in excess of actual incurred costs: This means that the IS function charges a markup or profit margin on top of its actual incurred costs to each user or business unit.For example, if a user or business unit consumes $100 worth of IS resources, the IS function will charge them $120, where $20 is the residual income for the IS function. This charging method has the disadvantage of discouraging efficient use of IS resources, as it increases the costs for the users and reduces their value for money. This charging method also creates a conflict between the interests of the IS function and the users, as the IS function benefits from increasing costs and profits, while the users suffer from paying more than they should.

Allocations based on the ability to absorb charges: This means that the IS function charges different amounts to different users or business units based on their ability to pay or their profitability. For example, if a user or business unit is more profitable or has a higher budget than another user or business unit, they will pay more for the same amount of IS resources. This charging method has the disadvantage of discouraging efficient use of IS resources, as it does not reflect the actual consumption or usage of each user or business unit, and does not provide any incentive to reduce costs or improve efficiency. This charging method also creates an unfair and arbitrary distribution of costs among the users or business units, as some paymore than others for no valid reason. References: 1: Charging Methods for IT Services - IT Process Wiki 2: IT Chargeback Methods - CIO Wiki 3: IT Chargeback - Wikipedia

The IS auditor’s best recommendation is to ensure that programmers cannot access code after the completion of program edits. This is because programmers who have access to code after editing may introduce unauthorized or malicious changes that could compromise the security, functionality, or performance of the application. By restricting access to code after editing, the organization can ensure that only authorized and tested code is released into production, and prevent any tampering or reoccurrence of the same issue.

 The organizational policies and procedures are the first source of guidance for an IS auditor when planning a customer data privacy audit. They provide the framework and objectives for ensuring compliance with legal and regulatory requirements, customer agreements and data classification. The IS auditor should review them first to understand the scope, roles and responsibilities, standards and controls related to customer data privacy in the organization. The other options are also important, but they are secondary sources of information thatshould be reviewed after the organizational policies and procedures. References: CISA Review Manual (Digital Version) 1, Chapter 2: Governance and Management of Information Technology, Section 2.5: Privacy Principles and Policies.