Sandbox security versus the evil Web
- — 01 October, 2008 09:02
Concerns about the class
But before reading the individual product reviews, let's discuss sandbox software in general. Sandbox protection products haven't gained a tremendous amount of traction with customers over the years for a number of legitimate reasons.
The first concern is accuracy. Every product failed one or more tests to varying degrees. All of them failed the Adobe Flash clipboard hijack exploit test, and most failed to accurately clean up from the XP Antivirus malware program. This was despite the fact that many sandbox vendors claimed to prevent all known and unknown attacks. You can see the results and failures in the many screen images and video files offered along with this review.
The question is, despite the dubious accuracy, do these products provide additional value? In most cases, the answer is yes. Most sandbox programs attempt to prevent any system modification and don't care whether a particular threat is "recognizable." But this causes a tremendous amount of false negatives, meaning real threats aren't identified as such, and leads to a second problem.
Inherent in many of the products is the idea that end-users must make a trust decision on whether to erase, save, or execute downloaded content. Taken to one extreme, if end-users erase all content after every session, how would their system, applications, or browsers receive upgrades or security patches? Taken to the other extreme, if users save or execute all content, they will end up infected or negate the need for the additional protection. Ultimately, with varying levels of assistance from the product, the end-user must make the key decision on whether or not to save and execute the data from each session.
Detecting what is and isn't malicious is becoming harder all the time. A large majority of malware is coming from innocent, legitimate Web sites (such as favorite news sites, online social portals, blogs, and so on) that are infected with harmful content, and the social engineering pitches to the end-user are getting more persuasive.
Gone are the days when phishing malware was easy to spot due to obvious grammar issues and misspellings. Today's crimeware poses as legitimate vendor patches, online malware removers ("You are infected and need to run this scanner!"), overdue bills, and legal notices. Because of these increasingly blurred distinctions, end-users can't always be sure which Web site content can be trusted and safely executed. And still users are forced to make a trust decision that twenty years of history shows they aren't adept at making. If users could make consistently correct trust decisions, would they need the protection that sandbox products provide in the first place?
Some of the products in this review, notably Sandboxie and SafeCentral, rarely made an attempt to inform the user whether a Web site or download was legitimate or malicious. The user had to make every trust decision. Other products attempted to tell the user which Web sites contained malware and which did not. Prevx did a fairly good job at this, while DefenseWall and ForceField were more hit than miss.
In many products, content downloaded during a browser session must be saved or discarded as a whole (in other words, everything or nothing), while other products, especially Sandboxie and DefenseWall, allow the user to pick and choose between individual objects. I enjoyed the detail Sandboxie showed, as it often allowed me to confirm whether or not something malicious had occurred (such as new files in System32), but it really is only useful for technical users.
Sandboxie and DefenseWall focused on protecting particular applications or sessions, while others fell into the more traditional role of a host intrusion prevention system (HIPS), protecting critical system areas regardless of the attack vector. I was impressed with Sandboxie's ability to ensure that additional child sessions were always launched in protected mode when instantiated by a protected parent process. This is important as the browser is becoming more of a launching point for the rest of our integrated applications. Malware writers are increasingly attacking the applications as operating systems and browsers get more secure.