Referral Spam

Referral spam is fake or bot visits arriving with a forged referrer so that some unwanted site's name appears in your referrers report.

Referral spam is an old trick: the spammer knows a site owner reads the referrers report, so by forging the referrer or fabricating a ghost visit it injects its own domain's name into that report, hoping you open it out of curiosity. It comes in two kinds: crawler spam that really hits the page, and ghost spam that never sees the site and sends fake data straight to the analytics system. Its harm is analytical, not security: it fills the real referral sources with noise, skews bounce rate and session duration, and unfiltered it drives decisions on contaminated data. The main defense is bot detection and excluding non-human traffic; because referral spam is almost always robotic, a tool that reports bot-free by default removes most of it automatically.