1. A collection of computers compromised by malicious code and controlled across a network. A programmed Internet-connected device that can be used to launch DDOS attacks [Distributed Denial of Service (DDoS) attacks], steal data, send spam, etc. Bots are frequently spread as email attachments and can compromise election office computers used to browse websites and support email activities.

Source: Glossary - Introduction to Information Technology for Election Officials, U.S. Election Assistance Commission,

2. A collection of zombie PCs [personal computers]. Botnet is short for robot network. A botnet can consist of tens or even hundreds of thousands of zombie computers. A single PC in a botnet can automatically send thousands of spam messages per day. The most common spam messages come from zombie computers. (McAfee Labs - Threat Glossary) .

Also, Botnets, or Bot Networks, are made up of vast numbers of compromised computers that have been infected with malicious code, and can be remotely-controlled through commands sent via the Internet. (CRS Report PL32114, 29 Jan 2008).

Source: Terms & Definitions of Interest for DoD Counterintelligence Professionals, Office of the National Counterintelligence,

3. A collection of computers infected with malicious bots. These can be fully remotely controlled by the attacker (the owner of the botnet). Depending on its size, a botnet may consist of several hundred to millions of compromised computers

Source: Information Assurance Situation in Switzerland and Internationally, Reporting and Analysis Centre for Information Assurance MELANI,

4. A collection of computers compromised by malicious code and controlled across a network without the owner’s knowledge or consent. (NICCS).

Source: The Cyber Glossary, National Security Archive, George Washington University,

5. A network of compromised computers (or bots) under unified command and control.

Source: U.S. Cyberspace Solarium Commission, March 2020,