Which type of malware spreads quickly through network shares without needing user interaction?

The type of malware that spreads quickly through network shares without requiring user interaction is a worm. Unlike viruses, which attach themselves to files and rely on user actions to propagate, worms are designed to replicate themselves and travel across networks autonomously. This self-replicating capability allows worms to exploit vulnerabilities in software, operating systems, or network configurations to spread rapidly from one system to another.

Worms can take advantage of open network shares, sending copies of themselves to other machines on the same network without needing any user to execute a file or click on a link. This makes them particularly dangerous, as they can compromise large numbers of systems in a short period, often leading to significant disruptions within organizations.

In contrast, a virus typically requires user action to spread, such as opening an infected email attachment or downloading a malicious file. Trojans disguise themselves as legitimate software and trick users into installing them, while adware is generally less harmful and mainly focuses on displaying advertisements rather than spreading across networks. Thus, the characteristic behavior of worms aligns them as the type of malware in question.