virus

A software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer.

“a true virus cannot spread to another computer without human assistance”

A harmful or corrupting agency.

“bigotry is a virus that must not be allowed to spread”

“the virus of jealousy is latent in everyone”

(virology) ultramicroscopic infectious agent that replicates itself only within cells of living hosts; many are pathogenic; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein.