What is the characteristic feature of a worm compared to a virus?

A worm is characterized by its ability to spread independently across networks without the need to modify other programs. This autonomous movement allows worms to reproduce and distribute themselves widely without user intervention, which distinguishes them from viruses. While viruses typically require some form of user interaction or the execution of a host program to propagate—such as opening an infected file—worms can exploit vulnerabilities in network protocols or utilize other mechanisms to replicate themselves and infect other systems seamlessly.

The ability to spread without user interaction emphasizes the virulence of worms, making them particularly dangerous in networked environments, whereas viruses rely on host programs for replication and often necessitate user actions for activation and spreading. This fundamental difference is crucial for understanding the operational mechanics of these types of malware in the realm of software development security.