Techno-virus

In an alternate timeline in which they upgraded Earth into Cyber-Earth in the year 2006, the Cybermen used what the Ninth Doctor called an airborne techno-virus containing nanites to convert the human population into Cyber-Warriors. Rose Tyler was a victim of this process, transforming into a Cyberman who attacked the Doctor, who was himself partially converted by the nanites, upgrading his right arm. Jackie Tyler was spared conversion within the shield of the flyer. (COMIC: Supremacy of the Cybermen)