Vikram Phatak (NSS Labs) evaluated the effectiveness of seven popular consumer endpoint security products to see which blocked variants of the Operation Aurora attack.
See http://nsslabs.blogspot.com/2010/03/vulnerabilities-exploits-payloads-and.html for the full report.
This test shows that not all security products are able to prevent computers from getting infected. If we would repeat this test with other malware types, then the list of vendors that “pass” and “fail” will be different. No anti malware program gives you 100% security: A second opinion scanner will be needed, even if it’s only for the sake of peace of mind.