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

• A. Polymorphic Virus
• B. Macro Virus
• C. Multipartite Virus
• D. Boot/Exe Exclusive Virus

Answer: (C)

Multipartite viruses use multiple infection vectors, targeting both the system boot sector and executable files. They place malicious code in the boot sector so it runs at startup, and they also attach to or infect executable programs so the payload spreads whenever those programs are executed. This dual approach makes them capable of propagating even if one infection path is cleaned, because the other path can reintroduce infection on reboot or on program use.

Other concepts describe different behaviors. Polymorphic viruses change their code to avoid detection but aren’t defined by a dual infection method. Macro viruses infect documents via macros rather than core system areas. A term suggesting infection limited to one vector would fail to explain an organism that reliably spreads through both boot sectors and program files.