CompTIA Updated CAS-005 Exam Questions and Answers by madeleine

Risk appetite is the amount of risk an organization is willing to accept to achieve its objectives. When operating with a constrained budget, understanding the organization's risk appetite is crucial because:

It helps prioritize security investments based on the level of risk the organization is willing to tolerate.

High-impact, low-likelihood events may be deemed acceptable if they fall within the organization's risk appetite, allowing for budget allocation to other critical areas.

Properly understanding and defining risk appetite ensures that limited resources are used effectively to manage risks that align with the organization's strategic goals.

The scenario describes a prolonged, stealthy operation where files were exfiltrated over three months via secure channels (TLS-protected HTTP) from unexpected systems, then ceased. This aligns with anAdvanced Persistent Threat (APT), characterized by long-term, targeted attacks aimed at data theft or surveillance, often using sophisticated methods to remain undetected.

Option A:Decrypting RSA with weak encryption implies a cryptographic attack, but TLS suggests modern encryption was used, and there’s no evidence of decryption here.

Option B:A zero-day attack exploits unknown vulnerabilities, but the duration and cessation suggest a planned operation, not a single exploit.

Option C:APT fits perfectly—slow, persistent exfiltration fromunusual systems indicates a coordinated, stealthy threat actor.

Option D:An on-path (man-in-the-middle) attack intercepts traffic, but there’s no indication of interception; the focus is on unauthorized transfers.

Homomorphic encryption allows computations to be performed on encrypted data without decrypting it, preserving confidentiality. However, its adoption faces significant challenges due to performance overhead. According to the CompTIA SecurityX CAS-005 study materials (Domain 3: Cybersecurity Technology, 3.3), homomorphic encryption requires substantial computational resources, which standard processors struggle to provide efficiently. Specialized hardware, such as coprocessors (e.g., GPUs or TPUs), is oftenneeded to handle the complex mathematical operations involved. The lack of widespread, optimized coprocessor support in existing infrastructure is a primary barrier to adoption.

Option A (Incomplete mathematical primitives):While early homomorphic encryption schemes had limitations, modern schemes (e.g., CKKS, BFV) have mature mathematical foundations, making this less of a challenge today.

Option B (No use cases):Use cases exist, such as secure cloud computing and privacy-preserving data analytics, so this is not accurate.

Option C (Quantum computers):Homomorphic encryption is not dependent on quantum computing, and quantum computers are unrelated to its current challenges.

Option D (Insufficient coprocessor support):This is the most accurate, as performance bottlenecks require specialized hardware that is not yet widely available or integrated.

The log shows an AXFR (zone transfer) query, which exposed internal DNS records, aiding lateral movement. Let’s evaluate:

A. Disabling DNS zone transfers:AXFR allows full DNS zone data to be transferred. Disabling it externally prevents attackers from mapping internal networks, directly mitigating this issue per CAS-005’s security operations focus.

B. Restricting to UDP/53:AXFR uses TCP/53, so this wouldn’t stop it.

C. DNSmasking:Obscures records but isn’t a standard term for this fix.