Which type of virus can change its code or appearance to evade detection from antivirus programs?

A polymorphic virus is designed to change its code or appearance each time it infects a new system. This characteristic enables it to evade detection by antivirus programs, which often rely on signature-based detection methods. By altering its code, a polymorphic virus can slip past defenses that are looking for known patterns associated with specific malware signatures. This adaptability makes it significantly more difficult for traditional antivirus solutions to recognize and eliminate these threats, as the virus can continuously modify itself to avoid being matched to previously identified code samples.

In contrast, other virus types, while dangerous, do not share this ability to alter their appearance dynamically. For example, a boot sector virus infects the boot sector of storage devices and is typically recognized based on its behavior rather than a changing code structure. An armored virus employs protective techniques to prevent itself from being easily analyzed or removed, but it does not change its signature like a polymorphic virus. A wisdom virus does not exist as a recognized category of computer virus in cybersecurity literature. This distinction underscores the unique and evasive nature of polymorphic viruses, making them a significant concern in the realm of cybersecurity.