There are two contending authoritative sources known for reviewing anti-malware products.
One source is av-test.org (Their most recent data is here).
The other source is av-comparatives. They have two reports, one that has results for tests of the on-demand abilities of anti-malware products, and the other that has results for tests of the retrospective/proactive properties of anti-malware products.
Right off the bat, it is interesting to see that there are places where there are large differences between the two testers.



