Types of IDS for Network Traffic Spikes

A.

The notification received by the security analyst indicates a spike in network traffic after working hours. This scenario suggests that the IDS (Intrusion Detection System) is likely an anomaly-based IDS.

Anomaly-based IDS is a type of intrusion detection system that works by comparing the current network traffic behavior against a baseline or a set of predefined rules. This baseline or rules define normal behavior or expected patterns of activity on the network. If the system detects network traffic that deviates from the established baseline, it generates an alert or notification to the security analyst.

In contrast, a signature-based IDS works by comparing the network traffic against a database of known attack signatures or patterns. When it detects a match between the network traffic and the known attack pattern, it generates an alert or notification.

A stateful IDS analyzes the state of network connections to detect and prevent attacks. It monitors the network traffic and tracks the state of each network connection, such as the sequence numbers and acknowledgement numbers, to detect any anomalous behavior.

A host-based IDS operates on individual hosts or endpoints rather than on the network as a whole. It monitors system logs, file changes, and other host-related events to detect any suspicious activity.

In summary, the scenario described in the question is most likely an example of an anomaly-based IDS because it is detecting a deviation from the established baseline or normal network traffic behavior.