A Zombie is a malicious program that is installed on a device that transforms it into a “zombie” that attacks other systems.
An example of a zombie is a host computer that is infected with a virus or Trojan horse. It then acts as a bot or is joined into a botnet and performs mundane but harmful automated attacks. Zombie computers and assemblages of them, for example botnets, often conduct e-mail spam, click fraud against pay-per-click (PPC) advertising, and launch [distributed] denial-of-service (DDoS, DoS) attacks.
“My friend’s Macbook got infected with malware and now his computer is a bitcoin-mining zombie. Does anyone know how to dislodge this from his system?”