It was only a matter of time, but the first security ISV has publicly announced a product that bypasses PatchGuard. Authentium, announced today that their Authentium ESP Enterprise Platform can bypass PatchGuard. In a world where less than 1% of known threats exploit the kernel in a way that PatchGuard will block, and where only 15 of 264 (less than 6%) Microsoft vulnerabilities from 2004-2006 would have been protected by PatchGuard, according to our calculations, I’m not sure whether to laugh or cry.

Patchguard is an attempt to close a software hole with more software. As Joanna Rutkowska has amply proven, there is no software-only solution to the rootkit problem. Hardware solutions, like Intel’s Vanderpool or AMD’s Pacifica are required to harden PatchGuard to the point it cannot be broken, but they will not be widely spread in the field for years to come. And in closing one small hole, it’s opening a host of others, like those addressed by the behavioral, anti-rootkit technology, and HIPs features we, and other vendors, have been working on for years. Arguably, our solutions are not immune to this same problem, the difference being that instead of one solution from a newbie security vendor, consumers today can deploy multiple solutions from many seasoned vendors to create a layered defense strategy, even at a desktop level.

So in the meantime, MS is going to try to put their fingers in the dike of PatchGuard holes, which are more valuable to security vendors than to malware authors, who can just avoid the kernel structures MS is trying to protect. In many ways, this is the final manifestation of the logical conclusion I came to when Greg Hoglund first announced his NT rootkit: We are, and always have, been locked in an arms race with the malware authors and hackers. Microsoft has just taken away our most effective weapons.

Microsoft is putting McAfee, Authentium, Symantec, Sunbelt and the rest of the security community in the interesting position of having to tell our customers that we can’t protect them beyond a reactive AV signature without “hacking” their operating system. So if we can’t protect them, and Microsoft can’t protect them (and won’t let us), what are consumers and enterprises to do? Right now, security vendors and Microsoft are in a very public standoff. It will be interesting to see what happens when Microsoft’s own customers chime in on this issue. What do you think?