What are spambots?

A spambot is a program designed to collect e-mail addresses from the Internet in order to build mailing lists for sending unsolicited e-mail, also known as spam. A spambot is a type of web crawler, that can gather e-mail addresses from Web sites, newsgroups, special-interest group (SIG) postings, and chat-room conversations. Because e-mail addresses have a distinctive format, spambots are easy to write. A number of legislators in the U.S. are reported to be devising laws that would outlaw the spambot. A number of programs and approaches have been devised to foil spambots. One such technique is known as address munging, in which an e-mail address is deliberately modified so that a human reader (and/or human-controlled Web browser) can decode it but a spambot cannot. This has led to the evolution of sophisticated spambots that can recover e-mail addresses from character strings that appear to be munged. The term spambot is sometimes used in reference to a program designed to prevent spam from reaching the subscribers of an Internet service provider (ISP). Such programs are more often called e-mail blockers or filters. Occasionally, such a blocker may inadvertently prevent a legitimate e-mail message from reaching a subscriber. This can be prevented by allowing each subscriber to generate a whitelist, or a list of specific e-mail addresses the blocker should let pass. Another type of spambot surfs the web, looking for forms to submit, and it submits spam e-mails to these web forms, often with OCR technology to bypass any CAPTCHAs. There are also spambots used to post spam links to guestbooks, wikis, blogs, forums and any other web forms to boost search engine ranking.