Which virus type attempts to install itself inside the file it infects?

Which virus type attempts to install itself inside the file it infects?

• A. Cavity virus
• B. Polymorphic virus
• C. Boot sector virus
• D. Trojan horse

Answer: (A)

The concept here is how a virus can embed its code inside an existing program. A cavity infection targets unused space inside a host executable and inserts the malicious code there, effectively installing itself inside the file you run. The original program’s entry point and behavior remain intact from the outside, so users and basic checks may not notice the infection until the program behaves oddly or is analyzed more deeply. When the infected program is executed, control can transfer to the virus code within that file. This differs from boot sector viruses, which infect the boot or master boot records and run before the operating system loads. It also differs from polymorphic viruses, which focus on changing their appearance to evade detection rather than where they reside inside a file. And a Trojan horse is malware that pretends to be legitimate software, not necessarily infecting other files by inserting itself into them.

The concept here is how a virus can embed its code inside an existing program. A cavity infection targets unused space inside a host executable and inserts the malicious code there, effectively installing itself inside the file you run. The original program’s entry point and behavior remain intact from the outside, so users and basic checks may not notice the infection until the program behaves oddly or is analyzed more deeply. When the infected program is executed, control can transfer to the virus code within that file.

This differs from boot sector viruses, which infect the boot or master boot records and run before the operating system loads. It also differs from polymorphic viruses, which focus on changing their appearance to evade detection rather than where they reside inside a file. And a Trojan horse is malware that pretends to be legitimate software, not necessarily infecting other files by inserting itself into them.