A zombie may refer to any of the following:
1. Term used to describe a process that is doing nothing but using system resources. This often occurs when a process has been abandoned by a previously running program.
2. A computer that has been maliciously setup to do work of another program or users. A zombie computer is often a computer or server that has been compromised to help a malicious user perform a Denial of Service attack (DoS) or DDoS attack.