Microsoft Security Essentials v4.6.305.0 was installed in the NSS Labs live stack exploit test harness as part of NSS’ continuous testing of consumer anti-malware products. Microsoft Security Essentials was subjected to thorough testing for exploit protection at the NSS facility in Austin, Texas, based on the Security Stack: Test Methodology v1.5. NSS test methodologies are available at nsslabstage.wpengine.com. This test includes a total of 1291 live (real-time) web-based exploits being used by threat actors in active campaigns identified with the NSS Cyber Advanced Warning System between February 1, 2015 and March 31, 2015. This test was conducted free of charge, and NSS did not receive any compensation for Microsoft’s participation.