Which of the following is NOT a common type of malware?

The correct answer identifies a firewall as not being a common type of malware. A firewall is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Its primary purpose is to establish a barrier between a trusted internal network and untrusted external networks, such as the internet. By functioning as a protective tool rather than an intrusive program, a firewall helps to prevent unauthorized access and cyber threats.

In contrast, worms, spyware, and ransomware are all categories of malware. Worms are self-replicating programs that spread across networks without the need for human intervention, often causing significant damage. Spyware secretly monitors user activity and collects information, potentially compromising privacy. Ransomware encrypts files on a victim’s device and demands payment for their release, causing operational disruptions and financial loss.

Understanding these distinctions is crucial for recognizing different cybersecurity threats and the protective measures necessary to mitigate them.