Which of the following is a sign that a computer may be infected with malware?

Frequent crashes are indeed a sign that a computer may be infected with malware. Malware can interfere with the normal functioning of a system, leading to instability, which manifests as programs crashing unexpectedly or the operating system failing to operate correctly. This can occur due to malware consuming system resources, corrupting files, or altering critical settings, all of which can compromise the stability of the system.

In contrast, faster performance than usual may be misleading, as it does not typically indicate an infection; rather, it might suggest that the system has been optimized or improved in some manner. Regular updates are generally a positive sign, indicating that the operating system or software is being maintained and potentially secured against vulnerabilities, not a symptom of infection. Increased battery life is usually a characteristic of well-optimized hardware or power-saving settings and doesn't correlate with malware presence. Therefore, frequent crashes serve as a reliable indicator of a potential malware issue.