Spam is the posting of advertisements, abusive, or unneeded messages on Internet forums. It is generally posted by automated spambots.Spambots are automated programs designed to register on forums, disseminate spam, and leave. They usually supply a fake name, freebase email address, and sometimes mask their true IP address. Spammers can set the message that the spambot will post. Most spambots target one specific forum software or hosting company. Spambots are easy to identify by the nature of the message they leave, or the links in the signature. A typical post contains no topical content, but is accompanied by either spam links in the post itself, or in the user's signature. Some spambots will never post, and rely on the links in their signature to increase their search engine visibility. Looking up the spambot's user name with a search engine will often reveal thousands of registrations in unrelated forums.
An example of a spambot which has gained some notoriety since November of 2006 is XRumer. XRumer attempts to bypass anti-spamming mechanisms put in place by forum administrators, with some success. It uses a database of known HTTP proxies to mask the IP address of the poster, making it difficult for administrators to use a naive IP-banning mechanism.