What is the MOST plausible cause of increased server resource consumption and unusual behavior within server logs?

The most plausible cause of increased server resource consumption and unusual behavior within server logs is malware infection. Malware can significantly affect server performance by utilizing excessive system resources, such as CPU and memory. It may operate stealthily in the background, executing various processes that can lead to increased bandwidth usage, excessive log entries, and overall system instability.

Malware can also compromise server security, causing various unusual activities that appear in logs, such as unauthorized access attempts or abnormal network traffic patterns. Monitoring logs may show data exfiltration attempts or unexpected commands being executed due to the presence of harmful software, further indicating that malware is the likely culprit behind such symptoms.

While hardware malfunction, network configuration errors, and legitimate user overload can also lead to resource consumption issues and unusual log entries, they typically do not have the same hidden, insidious effects associated with malware. Hardware problems might lead to errors or system crashes, and network configuration mistakes often cause connectivity issues. Legitimate user overload would not inherently result in unusual behavior, as it stems from expected user activities, which can usually be managed or anticipated. Thus, in the context of unusual behavior and specifically increased resource utilization linked to malicious intent, malware infection stands out as the most plausible cause.