What does a CAT-3 incident refer to under the US-CERT model for incident categorization?

A CAT-3 incident, according to the US-CERT model for incident categorization, refers to "Malicious code." This categorization includes incidents where malicious software such as viruses, worms, and Trojan horses is utilized to damage systems, steal data, or compromise system integrity.

Understanding the details of a CAT-3 incident is crucial because it highlights the use of malware, which can lead to severe consequences for organizations, including data breaches and significant operational disruptions. Identifying and categorizing incidents accurately helps organizations prioritize their response efforts and allocate resources effectively to mitigate the impacts of such incidents. By focusing on malicious code, the response teams can implement adequate detection, prevention, and recovery strategies specific to this kind of threat.

The other categories—unauthorized access, denial of service, and information disclosure—are important but pertain to different types of incidents that are classified under CAT-1 and CAT-2 categories within the US-CERT framework. Each category signifies different types of threats and thus requires tailored responses for effective incident management.