The glossary below contains many of the terms you will find in common use throughout the Symantec Security Response website. Please refer to this list to find definitions of terms and answers to other Internet security-related questions.

directory harvest attack

A tactic that spammers use to determine valid email addresses. A directory harvest attack occurs when a spammer sends a large quantity of possible email addresses to a site. An unprotected mail server rejects messages that are sent to invalid addresses. This behavior lets spammers know which email addresses are valid by checking the rejected messages against the original list.