That finding comes via a new report from independent testing firm NSS Labs, which studied the effectiveness of leading Windows endpoint--often referred to as antivirus--security suites.
In terms of their overall ability to block known exploits, NSS found that Kaspersky Internet Security 2012 stopped 92.2% of threats, while Alwil Avast Pro Antivirus 7 blocked 81.9%. Next in line were Symantec's Norton Internet Security version 19 (74.1%), AVG Internet Security 2012 (73.3%), ESET Smart Security 5 (70.7%), Trend Micro Titanium Maximum Security version 6 (69.8%), McAfee Internet Security 11 (65.5%), and Avira Internet Security 2012 (64.7%).
Meanwhile, Microsoft Security Essentials only blocked about half of the exploits it encountered, followed by F-Secure Agent version 1.57 (44.8%), Norman Security Suite 9.00 (42.2%), Panda Internet Security 2012 (38.8%), and Total Defense Internet Security Suite version 8 (34.5%).
According to a September 2012 antivirus market-share report from research firm OPSWAT, in North America, Microsoft controls 27% of the market, followed by Symantec (16%), Avast (11%), and AVG (10%).
[ Defense isn't enough to protect your systems. See Play Offense On Security In 2013: Gartner. ]
In today's era of advanced persistent threats, spear-phishing attacks, social engineering campaigns, and drive-by attacks, are endpoint security solutions performing well enough? The NSS Labs report suggests not. "Most vendors lack adequate protection against exploits," according to the report. As a result, "based on market share, between 65% and 75% of the world is poorly protected, and 75% to 85% in North America is poorly protected."
For its tests, NSS Labs used a Web server to attempt to infect its test PCs, but only using known exploits which have been seen on the Internet and in circulation for months, if not years. In other words, testers employed no zero-day vulnerabilities. In addition, the firm studied how different browsers reacted to the various exploits, using all versions of Internet Explorer since IE6, multiple versions of Firefox, as well as Apple Safari, and Google Chrome.
On that front, researchers issued a stark security warning--to consumers, but also applicable to businesses--that anyone still using IE6 "must be technically knowledgeable enough to employ other defenses, or will almost certainly be compromised." That's because when using IE6, only the McAfee endpoint security product blocked 100% of drive-by-download attacks, delivered via either HTTP or HTTPS. While four other products also performed well, Microsoft's wasn't one of them. "Ironically, Microsoft Security Essentials was one of the poorest performers at protecting users of IE6, and failed to block any of the Office 2003 exploits when delivered via Internet Explorer 6," according to the report.
Of course, security experts always recommend that businesses employ layered information security defenses, and not rely solely on antivirus software to block threats. According to NSS Labs, those extra layers of business defense should include, at a minimum, a robust patch management program, including rapid upgrading to the latest browser versions and browser plug-ins, as well as the use of an intrusion prevention system (IPS), especially in businesses that allow--explicitly or otherwise--employees to connect their own devices to the corporate network, per the bring-your-own-device (BYOD) movement.
While the report focuses on consumer-grade antivirus software, it's important to note that most endpoint security vendors' consumer-grade suites include a more sophisticated array of exploit-blocking tools than their enterprise-grade software. That's due in part to the industry assumption that for many consumers, the only defense standing between their PC and a malware infection is the antivirus software. Furthermore, those defenses are facing an ever-increasing number of threats, as the reported number of new vulnerabilities has been increasing by about 30% per year. Even one exploit that slips past the security defenses could result in an infection, allowing attackers to install additional malware onto the PC, or add the PC to their botnet.