Which of the following is a sign of malware on your device?

Frequent crashes and unexpected behavior are clear indicators of malware on your device. Malware often disrupts the normal functioning of a system by interfering with processes, causing applications to close unexpectedly, or leading to system instability. This erratic behavior can result in frequent crashes, making it difficult to use the device for its intended tasks. Other signs of malware may include sluggish performance or unusual pop-up messages, but the key characteristic here is the sudden onset of these problems without an obvious cause, suggesting that malicious software may be affecting the system's operations.

In contrast, faster performance than usual might indicate upgrades or optimizations rather than malware, while longer battery life and less storage space used are not typically associated with malware presence. These signs do not carry the same implication of compromise as unexpected crashes and behavior do.