What is malware?

Malware, short for "malicious software," refers specifically to software that is intentionally designed to perform harmful actions on computer systems, networks, or devices. This can include a variety of threats such as viruses, worms, trojans, ransomware, and spyware, all of which can cause significant damage to data, privacy, and system integrity. The primary characteristic that defines malware is its intent to disrupt, damage, or gain unauthorized access to computer systems and networks, which aligns with the definition provided in the correct answer.

In contrast, the other options refer to concepts that do not embody the characteristics of malware. A type of network protocol pertains to communication rules on a network, while security firewall configurations are defensive measures rather than offensive actions. Software that enhances computer performance is focused on optimization and efficiency rather than malicious intent, which further distinguishes it from the nature of malware. Therefore, the correct answer effectively captures the essence of what malware is and its purpose within the realm of cybersecurity threats.