Explanation: An intrusion detection system (IDS) is a device or software application that monitors network and/or system activities for malicious activities or policy violations and produces reports to a Management Station. Some systems may attempt to stop an intrusion attempt but this is neither required nor expected of a monitoring system. Intrusion detection and prevention systems (IDPS) are primarily focused on identifying possible incidents, logging information about them, and reporting attempts. In addition, organizations use IDPS for other purposes, such as identifying problems with security policies, documenting existing threats, and deterring individuals from violating security policies. As IDS detects and gives warning when the violation of security policies of the enterprise occurs, it is a detective control.
Incorrect Answers:
B: These controls make effort to reduce the impact of a threat from problems discovered by detective controls. As IDS only detects but not reduce the impact, hence it is not a corrective control.
C: As IDS only detects the problem when it occurs and not prior of its occurrence, it is not preventive control.
D: These controls make efforts to overcome the impact of the incident on the business, hence IDS is not a recovery control.