Which of the following issues would most likely occur on unencrypted devices?

While malware can certainly infect unencrypted devices, the presence of malware does not directly correlate to the lack of encryption. Malware infections can occur on any device, encrypted or not, and they exploit various vulnerabilities rather than specifically targeting encryption protocols.

Network spoofing involves impersonating another device or network to intercept communications. This issue is more related to network security than device encryption. An encrypted device can still be subject to network spoofing if it connects to a compromised network, making this not a direct consequence of lacking encryption.

A brute-force attack aims to gain unauthorized access by systematically guessing passwords or encryption keys. While it can target both encrypted and unencrypted devices, its effectiveness largely depends on the strength of the passwords used, rather than the encryption status of the device. Therefore, it is not specifically indicative of issues arising from unencrypted devices.