  a botnet is a collection of internet-connected programs communicating with other similar programs in order to perform tasks. this can be as mundane as keeping control of an internet relay chat (irc) channel, or it could be used to send spam email or participate in distributed denial-of-service attacks. the word botnet is a combination of the words robot and network. the term is usually used with a negative or malicious connotation. ==legal botnets== the term botnet is widely used when several irc bots have been linked and may possibly set channel modes on other bots and users while keeping irc channels free from unwanted users. this is where the term is originally from, since the first illegal botnets were similar to legal botnets. a common bot used to set up botnets on irc is eggdrop. ==illegal botnets== botnets sometimes compromise computers whose security defenses have been breached and control conceded to a third party. each such compromised device, known as a "bot", is created when a computer is penetrated by software from a malware (malicious software) distribution. the controller of a botnet is able to direct the activities of these compromised computers through communication channels formed by standards-based network protocols such as irc and hypertext transfer protocol (http). ==recruitment== computers can be co-opted into a botnet when they execute malicious software. this can be accomplished by luring users into making a drive-by download, exploiting web browser vulnerabilities, or by tricking the user into running a trojan horse program, which may come from an email attachment. this malware will typically install modules that allow the computer to be commanded and controlled by the botnet's operator. many computer users are unaware that their computer is infected with bots. depending on how it is written, a trojan may then delete itself, or may remain present to update and maintain the modules. the first botnet was first acknowledged and exposed by earthlink during a lawsuit with notorious spammer khan c. smith{{cite web|last=credeur|first=mary|title=atlanta
Botnets Computer_network_security Distributed_computing Multi-agent_systems Spamming