Which virus type infects both the boot sector and executable files?

• A. Macro Virus
• B. Polymorphic Virus
• C. Script Virus
• D. Multipartite Virus

Answer: (D)

Understanding how malware spreads through different infection vectors helps explain this. A multipartite virus is designed to work through more than one route: it can contaminate the boot sector so it persists when the machine boots, and it can also infect executable files so it spreads when programs are run. This dual capability is what makes it the best answer, because the others target a single pathway—macro viruses infect macros inside documents, script viruses target scripting environments, polymorphic viruses focus on changing their code to evade detection, and boot sector viruses concentrate on the boot sector rather than both vectors.