What type of malware spreads rapidly and replicates itself without user interaction?

The type of malware that spreads rapidly and replicates itself without requiring user interaction is indeed a worm. Worms are designed to exploit network vulnerabilities to propagate themselves from one computer to another independently. Unlike viruses, which typically need a host program to attach to and rely on user actions to activate, worms can move through networks and infect systems automatically, making them particularly dangerous due to their ability to cause widespread damage swiftly.

In contrast, spyware is a type of malware aimed at gathering information about a user or organization without their consent, primarily for the purpose of stealing sensitive data. While it can be harmful, it does not replicate itself. A virus, while also capable of spreading and causing harm, requires a host program and user interaction to propagate. Adware primarily generates revenue for its developer by displaying advertisements, and while it can be annoying and intrusive, it does not exhibit the self-replicating characteristics of worms. Hence, the defining feature of a worm is its ability to replicate and spread autonomously across networked devices, making it the correct answer in this context.