Symantec published Internet Security Report XI in its Security Response Weblog.
Here is the URL of the post on the blog: http://www.symantec.com/enterprise/security_response/weblog/2007/03/internet_security_threat_repor.html
The report describes various trends in web attacks, phishing, spam and security risks observed by the researchers.
The full paper is available here: http://eval.symantec.com/mktginfo/enterprise/white_papers/ent-whitepaper_internet_security_threat_report_xi_03_2007.en-us.pdf
Key findings are available here: http://eval.symantec.com/mktginfo/enterprise/white_papers/ent-whitepaper_internet_security_threat_report_xi_keyfindings_03_2007.en-us.pdf