What is an example of a security event?

A security event refers to any observable occurrence within a system or network that could potentially affect its security posture. In this context, malicious code detected in a system is a prime example of a security event. The detection of such code indicates an active threat, suggesting that an external entity has attempted to compromise the integrity, confidentiality, or availability of the system. This event requires immediate attention and further investigation to mitigate any possible risks associated with the detected malicious activity.

The other options, while they may be relevant to system operations, do not represent security events. Routine software updates and scheduled maintenance are standard operational tasks intended to maintain system performance and security, but they do not signify immediate threats or vulnerabilities. Random user logins, depending on the context, might not indicate security issues unless they are unauthorized or suspicious, making them less compelling as defining security events in a general sense.