Bayesian poisoning

Bayesian poisoning is a technique used by spammers to degrade the effectiveness of spam filters that rely on bayesian filtering. Bayesian filtering relies on Bayesian probability to determine whether an incoming mail is spam or is not spam ("ham").

A spammer practicing Bayesian poisoning will send out emails with large amounts of legitimate text (gathered from legitimate news or literary sources). If spam filters are trained using these emails, there is a much greater chance that they will also mark incoming non-spam emails as spam, due to similiarities between those and the literary sources used to generate the poisoned emails.

External links

• What is the effect of Bayesian poisoning
• Dispelling more Bayesian filtering myths