Hello,
you can also refer to AV-TEST and AV-Comparatives
http://www.av-test.org/en/tests/test-reports/julaug-2011/
http://www.av-test.org/en/tests/test-reports/julaug-2011/#corporate
http://www.av-comparatives.org/images/stories/test/corporate/corporate_review_2011.pdf
http://www.av-comparatives.org/images/stories/test/corporate/corporate_review_2010.pdf
http://www.av-comparatives.org/images/stories/test/corporate/Corporate_May_2009.pdf