Which of the following is NOT a type of malware?

Malware refers to malicious software designed to disrupt, damage, or gain unauthorized access to computer systems. Viruses, Trojans, and Worms are all types of malware. Viruses attach themselves to legitimate programs and spread when the host program is executed. Trojans disguise themselves as legitimate software but perform harmful actions once installed. Worms replicate themselves across networks without needing to attach to other software, often causing significant damage by consuming bandwidth or delivering payloads.

Firewalls, on the other hand, are not malware. They serve as a security measure, acting as barriers between trusted internal networks and untrusted external networks. Their primary function is to monitor and control incoming and outgoing network traffic based on predetermined security rules. As such, they help protect systems from malware and other threats rather than being a type of malware themselves. This highlights the importance of understanding the distinctions within cybersecurity, as knowing the functions of various tools and software safeguards against vulnerabilities.