What Does Armored Virus Mean?

An armored virus is a computer virus that contains a variety of mechanisms specifically coded to make its detection and decryption very difficult.

Techopedia Explains Armored Virus

Anti-virus researchers find out how a virus works by examining and following the code of the virus. An armored virus makes this difficult by making it hard to disassemble the virus. This gives the virus more time to propagate itself before researchers can create a countermeasure.