Which of the following trends would be of GREATEST concern when reviewing the performance of an organization's intrusion detection systems (IDSs)?

An increase in false negatives means the IDS is failing to identify actual malicious activity as an intrusion. This is highly critical because real threats are bypassing detection, potentially leading to successful breaches without warning, compromising the security posture.

An increase in false positives means the IDS is incorrectly flagging legitimate activity as malicious, leading to alert fatigue and wasted resources, but it does not directly indicate missed attacks.

A decrease in false positives is a positive trend, indicating improved accuracy and efficiency of the IDS.

A decrease in false negatives is a positive trend, meaning the IDS is becoming better at detecting actual attacks, which is desirable.