Cybersecurity Glossary: Terms Explained in Plain English | TecnetOne

What Is a Polymorphic Virus? Definition | TecnetOne Glossary

Written by Tecnet One | Oct 9, 2026, 6:49:54 PM

A polymorphic virus is malware that changes its appearance with each infection, typically by encrypting its code with a different key and altering the routine that decrypts it, so every copy looks different while doing the same thing. A metamorphic virus goes further and rewrites its entire code each time. Both aim to evade signature-based antivirus, which matches known code patterns.

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