Which virus type hides from antivirus by masking the original size of the file or temporarily placing a copy of itself on another drive, thus replacing the infected file with the uninfected file stored on the hard drive?

Which virus type hides from antivirus by masking the original size of the file or temporarily placing a copy of itself on another drive, thus replacing the infected file with the uninfected file stored on the hard drive?

• A. Cluster viruses
• B. Stealth virus
• C. Macro virus
• D. Encryption viruses

Answer: (A)

Stealth viruses are designed to slip past antivirus by concealing their presence. They intercept requests to access infected files and can present a clean version to the user or scanner, effectively hiding the damage. Techniques include masking the original size of the infected file and temporarily relocating a copy of themselves to another location, then swapping in a clean file stored on the drive. This makes the infection harder to detect during scans because the file appears normal and uninfected while the virus remains active elsewhere. This behavior differs from cluster viruses, which spread by infecting file clusters on the disk and don’t rely on concealment through file-size masking or swapping. Macro viruses embed their code in document macros, not through stealthy file replacement. Encryption viruses focus on encrypting files to lock them out rather than hiding the infection itself.

Stealth viruses are designed to slip past antivirus by concealing their presence. They intercept requests to access infected files and can present a clean version to the user or scanner, effectively hiding the damage. Techniques include masking the original size of the infected file and temporarily relocating a copy of themselves to another location, then swapping in a clean file stored on the drive. This makes the infection harder to detect during scans because the file appears normal and uninfected while the virus remains active elsewhere.

This behavior differs from cluster viruses, which spread by infecting file clusters on the disk and don’t rely on concealment through file-size masking or swapping. Macro viruses embed their code in document macros, not through stealthy file replacement. Encryption viruses focus on encrypting files to lock them out rather than hiding the infection itself.