Which of the following is not typically considered a cyber event?

System downtime due to maintenance is not typically considered a cyber event because it is a planned and controlled occurrence, unlike the other options, which involve security breaches or incidents that threaten the integrity, confidentiality, or availability of data and systems. In the context of cybersecurity, events like unauthorized data access, malware infections, and data exfiltration signify actual vulnerabilities or attacks on system security, where there is an intent to exploit or harm the system or its data. Maintenance-related downtime is a routine operational procedure and is therefore excluded from the category of cyber events, which focuses on security-related incidents.