CAS-005 Exam Questions & Answers

Based on the provided authentication logs, we observe that User1's accountexperienced multiple failed login attempts within a very short time span (at 8:01:23 AM on 12/15). This pattern indicates a potential brute-force attack or an attempt to gain unauthorized access. Here's a breakdown of why disabling User1's account is the appropriate first step:

Failed Login Attempts: The logs show that User1 had four consecutive failed login attempts:

VM01 at 8:01:23 AM

VM08 at 8:01:23 AM

VM01 at 8:01:23 AM

VM08 at 8:01:23 AM

Security Protocols and Best Practices: According to CompTIA Security+ guidelines, multiple failed login attempts within a short timeframe should trigger an immediate response to prevent further potential unauthorized access attempts. This typically involves temporarily disabling the account to stop ongoing brute-force attacks.

Account Lockout Policy: Implementing an account lockout policy is a standard practice to thwart brute-force attacks. Disabling User1's account will align with these best practices and prevent further failed attempts, which might lead to successful unauthorized access if not addressed.

CompTIA Security+ SY0-601 Study Guide by Mike Chapple and David Seidl

CompTIA Security+ Certification Exam Objectives

NIST Special Publication 800-63B: Digital Identity Guidelines

By addressing User1's account first, we effectively mitigate the immediate threat of a brute-force attack, ensuring that further investigation can be conducted without the risk of unauthorized access continuing during the investigation period.

ChaCha20-Poly1305is a cipher suite specifically designed for efficiency on systems with limited hardware resources. It offers high security with lower memory and CPU consumption compared to AES on certain platforms, especially mobile devices. TLS 1.3 supports ChaCha20-Poly1305 natively. CBC (Cipher Block Chaining) modes like IDEA-CBC and Camellia-CBC are less efficient and not recommended under TLS 1.3, and AES-GCM, while secure, can be less efficient than ChaCha20 on devices without AES hardware acceleration.

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Understanding the Security Event:

Administrator accounts are highly privilegedand require strict monitoring.

Server 4 shows failed login attempts for the administrator account.This could indicate abrute-force attack or unauthorized access attempt.

The fact thatnone of the admin login attempts were successfulsuggestssomeone was trying to guess the credentials.

Why Option D isCorrect:

Failed logins for administrator accounts are a critical security concern.

If an attacker gains access, they couldescalate privileges and compromise the network.

Investigatingunauthorized admin login attemptsshould be thetop priorityin a log audit.

Why Other Options Are Incorrect:

A (Endpoint not submitting logs):While this is concerning, it does not indicate anactive attack.

B (Lateral movement):There's no evidence of a compromised account moving between servers yet.

C (Misconfigured syslog server):False negatives are a possibility, but thefailed admin loginsare real.

CompTIA SecurityX CAS-005 Official Study Guide:SIEM & Incident Analysis

MITRE ATT&CK (T1078.002):Valid Accounts - Administrator Compromise

User and Entity Behavior Analytics (UEBA) is the best solution to help the company overcome challenges associated with suspicious activity that cannot be categorized by traditional detection tools. UEBA uses advanced analytics to establish baselines of normal behavior for users and entities within the network. It then identifies deviations from these baselines, which may indicate malicious activity. This approach is particularly effective for detecting unknown threats and sophisticated attacks that do not match known indicators of compromise (IoCs).