What type of malware is designed to replicate itself and spread to other computers?

The correct answer is a virus. A virus is a type of malware specifically designed to replicate itself and spread to other computers by attaching itself to legitimate programs or files. When the infected program is executed, the virus activates and can copy itself onto other files and programs on the same computer or to others via methods like email attachments or shared drives.

In contrast, while worms also replicate and spread across networks, they do so independently and do not require host programs or user intervention, distinguishing them from viruses. Trojans, on the other hand, masquerade as legitimate software to trick users into installing them but do not self-replicate. Lastly, rootkits are designed to gain unauthorized access to systems and maintain that access, but they do not have the capability to replicate like viruses or worms. Understanding these distinctions is crucial for identifying and mitigating different types of malware threats.