Researchers backdoor a phishing kit, gather data on phishing scams over 15 months ...Phishers often set up their fraudulent sites using ready-made “phish kits” — collections of HTML, text and images that mimic the content found at major banks and e-commerce sites. Typically, phishers stitch the kits into the fabric of hacked, legitimate sites, which they then outfit with a “backdoor” that allows them to get back into the site at any time...
About a year and a half ago, investigators at Charleston, S.C. based PhishLabs found that one particular backdoor that showed up time and again in phishing attacks referenced an image at a domain name that was about to expire. When that domain finally came up for grabs, PhishLabs registered it, hoping that they could use it to keep tabs on new phishing sites being set up with the same kit.
The trick worked: PhishLabs collected data on visits to the site for roughly 15 months, and tracked some 1,767 Web sites that were hacked and seeded with the phishing kit that tried to pull content from the domain that PhishLabs had scooped up.
Additional Details here:
http://krebsonsecurity.com/2010/05/teach-a-man-to-phish/