spamfaqs.com

Most forum spam consists of links to external sites, with the dual goals of increasing search engine visibility in highly competitive areas such as weight loss, pharmaceuticals, gambling, pornography, real estate or loans, and generating more traffic for these commercial websites. Some of these links contain code to track the spambot’s identity if a sale goes through, when the spammer behind the spambot works on commission.

Spam posts may contain anything from a single link, to dozens of links. Text content is minimal, usually innocuous and unrelated to the forum’s topic. Such text is included to prevent the post being caught by automated spam filters that prevent posts which consist solely of external links from being submitted. Full banner advertisements have also been reported.

Alternately, the spam links are posted in the user’s signature, in which case the spambot will never post. The link sits quietly in the signature field, where it is more likely to be harvested by search engine spiders than discovered by forum administrators and moderators.

Recently, a very destructive forum spam attack has been propagated by inserting into comments redirect domains with an automated posting script like Xrumer. These domains redirect a user to pornographic Websites. If a user clicks on the image or attempts to close the Website an ActiveX codec will be downloaded as a Zlob Trojan.