Which virus type hides from antivirus by concealing the original file size or presenting a copy of itself elsewhere while the infected file remains?

Which virus type hides from antivirus by concealing the original file size or presenting a copy of itself elsewhere while the infected file remains?

• A. System Sector Virus
• B. Stealth virus
• C. Multipartite virus
• D. Macro virus

Answer: (B)

Stealth viruses rely on deception to avoid detection. They conceal their changes so the system or antivirus software sees an uninfected file. A classic trick is to report the original file size or contents, even though the infected code is present. In some variants, the virus keeps a copy of itself elsewhere and presents a clean version of the file to the user or to the scanner, while the malicious payload remains hidden. This makes the infection hard to spot with straightforward checks like file size or reading the file’s contents. This approach is what distinguishes stealth viruses from other types. A system/boot-sector virus focuses on the boot area rather than hiding modifications; a multipartite virus infects multiple vectors; a macro virus hides inside document macros. The stealth behavior specifically targets evasion by presenting a trusted view of the file while the infection persists.

Stealth viruses rely on deception to avoid detection. They conceal their changes so the system or antivirus software sees an uninfected file. A classic trick is to report the original file size or contents, even though the infected code is present. In some variants, the virus keeps a copy of itself elsewhere and presents a clean version of the file to the user or to the scanner, while the malicious payload remains hidden. This makes the infection hard to spot with straightforward checks like file size or reading the file’s contents.

This approach is what distinguishes stealth viruses from other types. A system/boot-sector virus focuses on the boot area rather than hiding modifications; a multipartite virus infects multiple vectors; a macro virus hides inside document macros. The stealth behavior specifically targets evasion by presenting a trusted view of the file while the infection persists.