What type of security control alerts the administrator about suspicious activities by monitoring inbound and outbound packets?

The correct answer to the question regarding which type of security control alerts the administrator about suspicious activities by monitoring inbound and outbound packets is the host intrusion detection system (HIDS).

A host intrusion detection system is designed to monitor the behavior and activities on a specific device or host. By analyzing the patterns of incoming and outgoing packets, a HIDS can identify potential security threats, such as unauthorized access, malicious activity, or policy violations. It does this by checking the traffic against a database of known attack signatures or by using anomaly detection techniques to identify unusual behavior that deviates from established baselines.

The role of a HIDS is crucial because it provides visibility at the individual host level, allowing administrators to respond quickly to suspicious activities that may indicate a compromise. This proactive monitoring can be vital for maintaining the security and integrity of sensitive data and systems.

In contrast, other options like network intrusion detection systems (NIDS) focus on monitoring the entire network and typically identify threats based on traffic across different hosts rather than individual devices. Meanwhile, firewalls primarily serve as barriers to block unauthorized access rather than actively scanning for suspicious activity, and intrusion prevention systems (IPS) can take action to block threats but may not be solely focused on alerting as their primary function.