Question 49 - 312-38 discussion

A host-based intrusion detection system (HIDS) produces a false alarm because of the abnormal behavior of users and the network. A host-based intrusion detection system (HIDS) is an intrusion detection system that monitors and analyses the internals of a computing system rather than the network packets on its external interfaces. A host-based Intrusion Detection System (HIDS) monitors all or parts of the dynamic behavior and the state of a computer system. HIDS looks at the state of a system, its stored information, whether in RAM, in the file system, log files or elsewhere; and checks that the contents of these appear as expected.

Answer option D is incorrect. A network intrusion detection system (NIDS) is an intrusion detection system that tries to detect malicious activity such as denial of service attacks, port scans or even attempts to crack into computers by monitoring network traffic. A NIDS reads all the incoming packets and tries to find suspicious patterns known as signatures or rules. It also tries to detect incoming shell codes in the same manner that an ordinary intrusion detection system does.

Answer option A is incorrect. IPS (Intrusion Prevention Systems), also known as Intrusion Detection and Prevention Systems (IDPS), are network security appliances that monitor network and/or system activities for malicious activity. The main functions of "intrusion prevention systems" are to identify malicious activity, log information about said activity, attempt to block/stop activity, and report activity. An IPS can take such actions as sending an alarm, dropping the malicious packets, resetting the connection and/or blocking the traffic from the offending IP address. An IPS can also correct CRC, unfragment packet streams, prevent TCP sequencing issues, and clean up unwanted transport and network layer options.

Answer option C is incorrect. DMZ, or demilitarized zone, is a physical or logical subnetwork that contains and exposes an organization's external services to a larger untrusted network, usually the Internet. The term is normally referred to as a DMZ by IT professionals. It is sometimes referred to as a Perimeter Network.

The purpose of a DMZ is to add an additional layer of security to an organization's Local Area Network (LAN); an external attacker only has access to equipment in the DMZ rather than any other part of the network.