Which of the following is NOT a symptom of a malware infection?

Increased processing speed is not a symptom typically associated with a malware infection. In fact, malware generally results in sluggishness or decreased performance due to the additional resources it consumes while running malicious processes in the background. Malware can lead to system slowdowns because it often engages in activities such as stealing data, generating unwanted network traffic, or utilizing system resources for nefarious purposes.

In contrast, the other options – inaccessible files and applications, strange noises, and unusual error messages – are all common indicators of a malware infection. Inaccessible files may result from ransomware enciphering data or other malicious activities that disrupt access. Strange noises can occur when malware causes hardware to behave unusually, or when changes in performance lead to atypical sounds from the hardware. Unusual error messages may reflect conflicts or issues caused by the presence of malicious software, indicating that the system is experiencing unexpected problems as a result of the infection.