Intrusion Prevention scans all the network traffic that enters and exits your computer and compares this information against a set of attack signatures. Attack signatures contain the information that identifies an attacker's attempt to exploit a known operating system or program vulnerability. Intrusion Prevention protects your computer against most common Internet attacks.

For more information about the attacks that Intrusion Prevention blocks, go to the following URL:
http://www.symantec.com/business/security_response/attacksignatures

If the information matches an attack signature, Intrusion Prevention automatically discards the packet and breaks the connection with the computer that sent the data. This action protects your computer from being affected in any way.

Intrusion Prevention relies on an extensive list of attack signatures to detect and block suspicious network activity. You should run LiveUpdate regularly to ensure that your list of attack signatures is up to date.