A heuristic intrusion detection system (IDS) provides the most protection against emerging threats, as it uses behavioral analysis and anomaly detection to identify unknown or zero-day attacks. A heuristic IDS can adapt to changing patterns and learn from previous incidents, making it more effective than a signature-based IDS, which relies on predefined rules and signatures to detect known attacks. A demilitarized zone (DMZ) is a network segment that separates the internal network from the external network, and it can provide some protection against external threats, but not against internal or emerging threats. Real-time updating of antivirus software is important to protect against malware, but it may not be sufficient to prevent new or sophisticated attacks that exploit unknown vulnerabilities. References: CISA Review Manual (Digital Version) 1, page 452-453.

A web proxy server for corporate connections to external resources reduces organizational risk by anonymizing users through changed IP addresses. A web proxy server is an intermediarybetween the web and client devices, that can provide proxy services to a client or a group of clients1. One of the main benefits of using a web proxy server is that it allows users to change their IP address andlocation, circumventing geoblocking and hiding their identity from the target website2.
Anonymizing internal IP addresses is important for online security, as it helps protect the organization from several threats. If an attacker controls a server that employees connect to, the outgoing IP address of the organization's router is logged on the server. This IP address can be used by the attacker to launch a denial-of- service (DoS) attack or to create more targeted attacks such as phishing2. With a web proxy server, the IP shown in web logs is the web proxy's, which means an attacker would not have access to theorganization's router outgoing IP address2.
Anonymizing outgoing IP addresses is also important when carrying out sensitive actions online, such as law enforcement investigations or competitive intelligence. A web proxy server can help users avoid exposing their internal IP address that leads back to their organization, and instead use a third-party web proxy that provides more anonymity2.
The other options are not directly related to reducing organizational risk by using a web proxy server. Providing multi-factor authentication for additional security (option B) is a benefit of some web proxy servers, but it is not the main purpose of using a web proxy server3. Providing faster response than direct access(option C) is a benefit of some web proxy servers that cache content forbetter data transfer speeds and less bandwidth usage, but it is not directly related to reducing organizational risk1. Load balancing traffic to optimize data pathways (option D) is a benefit of some web proxy servers that distribute traffic across multiple servers, but it is not directly related to reducing organizational risk4.
References: 1: Proxy servers and tunneling 2: Multi-factor authentication: How to enable 2FA and boost your security 3: What Is Multi-factor Authentication (MFA) Security? 4: How it works: Microsoft Entra multifactor authentication

A digital envelope combines the strengths of symmetric and asymmetric cryptography. The message itself is encrypted using a fast symmetric algorithm. The session key used for symmetric encryption is then encrypted using the recipient's public key. This ensures efficiency (large data encrypted quickly with symmetric keys) and security (session key securely transmitted using asymmetric encryption). Options A, C, and D describe other cryptographic processes (compression, hashing, or digital signatures) but do not correctly represent a digital envelope. ISACA training materials and CISA manuals highlight this hybrid approach as the standard method for secure data transmission.
References (ISACA): CISA Review Manual - Cryptography Concepts; ISACA Glossary.

The most effective way for an organization to help ensure agreed-upon action plans from an IS audit will be implemented is to ensure ownership is assigned. This means that the management of the audited area should accept responsibility for implementing the action plans and report on their progress and completion to the audit committee or senior management. This will ensure accountability, commitment, and follow-up for the audit recommendations34. References: 3: CISA ReviewManual (Digital Version), Chapter 1: The Process of Auditing Information Systems, Section 1.6: Reporting, page 41 4: CISA Online Review Course, Module 1:
The Process of Auditing Information Systems, Lesson 1.6: Reporting

Write access to production program libraries presents the greatest risk when granted to a new member of the system development staff. Production program libraries contain executable code that runs on live systems and supports critical business functions. Write access allows a user to modify or delete existing programs, or add new programs to the library. If a user were to make unauthorized or erroneous changes to production programs, it could cause serious disruptions, errors, or security breaches in the organization's operations.
Therefore, writeaccess to production program libraries should be restricted to authorized personnel only, and subject to strict change management controls.