Packet Payload and Header Analysis

A.

Because a network-based IDS reviews packets and headers, denial of service attacks can also be detected.

This question is an easy question if you go through the process of elimination.When you see an answer containing the keyword: ALLIt is something a give away that it is not the proper answer.On the real exam you may encounter a few question where the use of the work ALL renders the choice invalid.Pay close attention to such keyword.

The following are incorrect answers: Even though most IDSs can detect some viruses and some password guessing attacks, they cannot detect ALL viruses or ALL password guessing attacks.

Therefore these two answers are only detractors.

Unless the IDS knows the valid values for a certain dataset, it can NOT detect data corruption.

Reference used for this question: KRUTZ, Ronald L.

& VINES, Russel.

D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 48.

The correct answer is A. Detection of denial of service.

A network-based intrusion detection system (IDS) monitors network traffic to detect signs of security threats or attacks. Network-based IDS examines the packet headers and payloads to identify patterns that match known attack signatures.

Denial of Service (DoS) is an attack in which an attacker attempts to make a computer or network resource unavailable to its intended users by overwhelming the targeted system with traffic or by sending it information that triggers a crash.

A network-based IDS can detect DoS attacks by analyzing traffic patterns, identifying traffic that is abnormal, and correlating traffic from multiple sources that are aimed at a single target. For example, if an IDS detects a large number of requests from multiple sources to a single web server, it may alert the security administrator of a potential DoS attack.

The other answer choices are not accurate because network-based IDS systems cannot detect all viruses, data corruption or all password guessing attacks.

While network-based IDS may detect some viruses, the primary focus of such systems is on detecting attacks that exploit network vulnerabilities, and they do not have the ability to scan for all types of malware. Data corruption may also occur at the application layer, which may not be monitored by network-based IDS. Similarly, while network-based IDS may detect some password guessing attacks, it is not possible to detect all possible password guessing techniques, such as offline brute-force attacks.