What type of malware is designed to replicate itself and spread across systems?

The type of malware designed to replicate itself and spread across systems is a worm. Worms are a specific classification of malware that can independently reproduce and propagate through networks without requiring human intervention, unlike other forms of malware. They exploit vulnerabilities in operating systems or applications to move from one computer to another, often causing harm to systems and networks in the process.

In contrast, adware typically displays unwanted advertisements on a user's device but does not replicate itself. Trojans disguise themselves as legitimate software to trick users into downloading them, but they do not have the ability to independently replicate across systems. Spyware, designed to secretly gather user information, also lacks the self-replicating capability characteristic of worms. This unique ability to autonomously propagate makes worms particularly concerning in cybersecurity.