Detect DNS obfuscation using @ symbol

One of the tricks used in phishing is obfuscating the domain name in a URL by using the @ symbol. This technique goes all the way back to the original RFC for URLs, RFC 1738. When you specify an @ in the DNS portion of a URL it denotes that the left side of the DNS name holds a username and password for authentication to the server on the right side of the @ sign. Unfortunately, an attacker can use this technique to trick a user by formatting the URL as http://www.trusteddomain.com@www.realdomain.com/. When a user sees the link may they think they're going to www.trusteddomain.com when in fact they are going to www.realdomain.com. For a working example, try this: http://www.google.com@www.bing.com/. This query finds this technique in URLs embedded within e-mails and highlights the fake and real domains.