What type of malicious software spreads itself from computer to computer?

The correct identification of a worm as the malicious software that spreads itself from computer to computer is due to its unique operational characteristics. Unlike viruses, which often attach themselves to legitimate programs and require some form of user interaction to propagate, worms are standalone software that can replicate and spread autonomously across networks. They exploit vulnerabilities in operating systems or network protocols, allowing them to infect devices without any user intervention. This self-replicating feature enables worms to proliferate rapidly, often leading to significant network congestion and widespread infections.

In contrast, while viruses also spread between computers, they do so by attaching to files or programs and depend on users executing those files for dissemination. Trojans, on the other hand, disguise themselves as legitimate applications, tricking users into installation but do not inherently propagate themselves. Spyware is primarily designed to gather information from the user's device without their knowledge and does not focus on self-replication or spreading. Thus, a worm's ability to independently spread across systems distinctly qualifies it as the answer to the question regarding autonomous self-propagation.