Megatron's cyber-virus fuses human DNA with Transformer central circuitry. The resulting virus spreads organically, then solidifies into metal, transforming Earth's landscape into a semblance of the planet Cybertron.
Once it begins spreading, the virus is self-sustaining.
Megatron created the cyber-virus by merging the essences of Lazarus's captured soldiers with the captured Autobots. The process left the Autobots near death, and the humans... not-so-near.
Wheeljack invented an anti-viral weapon, directly channeling the Autobots' life-energy to halt the virus's progress and reverse the changes it had wrought.
Though the cyber-virus's transformation was reversed, the humans transformed by it seem not to have survived the reversion.
- The cyber-virus was not named in the course of Prime Directive proper; the term comes from advertising copy hyping upcoming issues.