phage

( n.)

   A  program  that modifies other programs or databases in unauthorized
   ways;  esp. one that propagates a {virus} or {Trojan horse}. See also
   {worm},  {mockingbird}. The analogy, of course, is with phage viruses
   in biology.

[glossary]
[Reference(s) to this entry by made by: {science-fiction fandom}{Trojan horse}{virus}]