What is the primary purpose of a host-based intrusion detection system?

The primary purpose of a host-based intrusion detection system (HIDS) is to monitor individual devices for malicious activity. HIDS operates at the host level, analyzing the system's activities, including file modifications, system calls, and user account activities, to detect unauthorized access, policy violations, or other suspicious behaviors that could indicate an intrusion.

By focusing on specific devices rather than the entire network, HIDS can provide detailed insight into the security status of those devices, enabling administrators to respond quickly to potential threats. This level of monitoring is crucial for identifying attacks that may have bypassed network defenses, as it allows for a more granular approach to security.

In contrast, creating firewalls is a function typically associated with network security appliances that manage traffic at the network perimeter, while protecting the network perimeter involves broader measures that include firewalls, intrusion prevention systems, and more. Installing software updates automatically aids in maintaining security and software integrity but does not constitute the primary function of HIDS.