Which cyber event category is associated with the installation of malicious software?

The category associated with the installation of malicious software is Malicious Logic. This term specifically encompasses events where software is deliberately created to cause harm, disrupt services, or gain unauthorized access to systems. Malicious software, or malware, can include viruses, worms, trojan horses, and ransomware, all designed to perform harmful actions within a network or system upon installation.

In contrast, the other categories pertain to different actions that do not specifically relate to the installation of harmful software. Non-Compliance Activity refers to instances where policies or regulations are not followed, which does not inherently involve malware. Investigating events are about examining incidents to determine whether a security breach occurred but do not imply the presence of malicious software. User Level Intrusion relates to unauthorized access by a user but does not specifically indicate that malware has been installed. Thus, Malicious Logic is the most accurate categorization for events involving the installation of malicious software.