Online attackers recognize that the Achilles heel in virtually any computer or network security scenario is the individual sitting behind the keyboard. There is no need to waste time or energy figuring out how to circumvent security controls and spread malware if you can just dupe naïve users into voluntarily running the malware.
NSS Labs reviewed Internet Explorer 8 and 9, Firefox 3.6, Safari 5, Chrome 6, and Opera 10 to see how well each browser helps users recognize and avoid these attacks. Data was collected 24/7 for eleven days, with 39 discrete tests run every six hours. The testing included 636 URLs identified as potentially malicious.
The NSS Labs Web Browser Security Socially-Engineered Malware Protection report clarifies the definition of a socially-engineered malware URL for the purposes of this testing: “a Web page link that directly leads to a download that delivers a malicious payload whose content type would lead to execution, or more generally a Web site known to host malware links. These downloads appear to be safe, like those for a screen saver application, video codec upgrade, etc., and are designed to fool the user into taking action. Security professionals also refer to these threats as “consensual” or “dangerous” downloads.”
Opera does not have any security controls specifically designed to protect users from these types of attacks. However, Chrome, Firefox, and Safari do. All three rely on the Google Safe Browsing API which performed well below Microsoft’s SmartScreen technology in previous testing. With the introduction of Google Safe Browsing v2, though, all three browsers experienced a significant decline from their already relatively low ability to identify and block malicious sites.
Meanwhile, Internet Explorer widened the gap. Internet Explorer 8 improved its results over the previous study–increasing from an 85 percent block rate to 90 percent. Internet Explorer 9, though–which wasn’t available during the previous study–was nearly flawless.
The NSS Labs Results Summary explains, “Windows Internet Explorer 9 (still in beta) caught an exceptional 99 percent of the live threats, in part due to a new application reputation system, leading the non-IE pack by 80 percent. IE9’s protection includes SmartScreen URL filtering, also included in IE8, and SmartScreen Application Reputation, which is new to IE9.”
The new security control in IE9 analyzes data to determine the reputation of a given file in an attempt to minimize the pop-up alerts displayed to users while still identifying potentially malicious executables. A post from October on the IEBlog explains the new IE9 SmartScreen Application Reputation protection. “With SmartScreen Application Reputation, IE9 warns you before you run or save a higher risk program that may be an attempt to infect your computer with socially engineered malware. IE9 also stays out of the way for downloads with an established reputation.”
To be fair, the NSS Labs report is focused on a specific type of threat. NSS Labs did not evaluate browser security in terms of flaws or vulnerabilities in the browsers themselves, or within browser add-ins. However, socially-engineered attacks are prevalent and increasing, and it seems that IE–whether IE8 or IE9–is uniquely prepared to help defend users from the threat.