Intrusion Detection Systems (IDS) in Cybersecurity - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary function of an Intrusion Detection System (IDS)?

Choose the best description of what an IDS does in a computer network.

A It manages user passwords and authentication credentials.

B It blocks all incoming traffic to prevent unauthorized access.

C It monitors network or system activities for malicious actions or policy violations and alerts administrators.

D It encrypts data to protect it from being intercepted during transmission.

💡 Hint

Think about what an IDS does after detecting suspicious activity.

An IDS watches network or system activity to find signs of attacks or policy breaches and then alerts the security team. It does not block traffic or encrypt data.

📋 Factual

intermediate

Which type of IDS analyzes network traffic to detect suspicious patterns?

Select the IDS type that inspects data packets traveling through the network.

A Host-based IDS (HIDS)

B Anomaly-based IDS

C Signature-based IDS

D Network-based IDS (NIDS)

💡 Hint

Consider which IDS type is placed on the network to watch traffic.

Network-based IDS (NIDS) monitors network traffic to detect suspicious patterns. Host-based IDS runs on individual devices.

🔍 Analysis

advanced

What is a key difference between signature-based and anomaly-based IDS?

Analyze the following statements and select the correct difference.

A Signature-based IDS uses machine learning; anomaly-based IDS uses fixed rules.

B Signature-based IDS detects attacks by matching known patterns; anomaly-based IDS detects deviations from normal behavior.

C Signature-based IDS can detect unknown attacks; anomaly-based IDS cannot.

D Signature-based IDS requires no updates; anomaly-based IDS requires constant signature updates.

💡 Hint

Think about how each IDS identifies threats.

Signature-based IDS looks for known attack patterns, while anomaly-based IDS identifies unusual behavior that differs from normal activity.

❓ Reasoning

advanced

Why might an IDS generate false positives, and what is a common consequence?

Choose the best explanation for why false alarms occur and their impact.

A False positives happen when normal activity is mistaken for attacks, causing unnecessary alerts and possible alert fatigue.

B False positives occur when the IDS fails to detect real attacks, leading to security breaches.

C False positives are caused by hardware failures, resulting in system crashes.

D False positives happen when the IDS blocks legitimate users, causing denial of service.

💡 Hint

Consider what happens when the IDS mistakes safe actions for threats.

False positives are alerts triggered by normal behavior mistaken as malicious, which can overwhelm security teams and reduce trust in alerts.

❓ Comparison

expert

Compare Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS). Which statement is true?

Select the option that correctly distinguishes IDS from IPS.

A IDS only detects and alerts on threats; IPS can detect and actively block threats in real time.

B IDS blocks malicious traffic automatically; IPS only logs suspicious activity.

C IDS requires no network placement; IPS must be installed on every host.

D IDS and IPS perform the exact same functions with no differences.

💡 Hint

Think about whether the system takes action or just reports.

IDS monitors and alerts on threats but does not block them. IPS can detect and also block or prevent attacks in real time.