Out of the following, which is a common symptom when a malware infection is present on multiple internal computers?

When assessing a malware infection present on multiple internal computers, one notable symptom is the slow performance of applications. This can occur because malware often consumes system resources as it operates in the background, executing its malicious tasks, which can include data theft, sending out spam, or spreading to other systems. As the malware utilizes CPU and memory resources, legitimate applications may struggle to run efficiently, causing noticeable slowdown across multiple computers within the same network.

Other symptoms, while they can also indicate malware presence, may not be as universally experienced on all infected machines. For instance, unusual pop-up messages might emerge due to specific types of adware or rogue software, while frequent disconnections from the network may indicate issues with the network configurations or specific types of malware. Random system reboots may occur due to rootkits or particularly aggressive forms of malware but are not always a direct result of malware activity across multiple systems. Thus, slow application performance stands out as a common, widespread symptom indicative of a potential malware infection affecting numerous internal machines.