What best describes malware that spreads rapidly through network services without user interaction?

The type of malware that spreads rapidly through network services without requiring user interaction is best described as a worm. Worms are designed to exploit vulnerabilities in network protocols and software to propagate themselves from one system to another autonomously. This means that worms can replicate and distribute themselves across computers within a network without needing to be activated by a user, making them particularly dangerous and efficient at causing widespread damage.

In contrast, a virus requires user action to spread, such as running an infected program or opening a file. Trojans disguise themselves as legitimate software, tricking users into executing them, but do not have the capability to self-replicate across a network. Spyware is primarily used for collecting information from a user’s device without their consent, rather than spreading itself through a network. Therefore, the unique characteristic of worms is their ability to autonomously spread and infect systems, effectively making them distinct from the other types of malware listed.