Spoofing is a term used to describe methods of faking various parts of the browser user interface. This may include the address or location bar, the status bar, the padlock, or other user interface elements. Phishing attacks often utilize some form of spoofing to help convince the user to provide personal information. If a user's browser is vulnerable to spoofing, they are more likely to fall victim to a phishing attack. You can search the US-CERT and CERT/CC web sites for malicious scripting and content vulnerabilities at the following URL: http://search.us-cert.gov (use the search term browser+spoof). The US-CERT document "Technical Trends in Phishing Attacks" (available at www.us-cert.gov/reading_room/phishing_trends0511.pdf) has more information about spoofing and phishing techniques.