Hacking PatchGuard

By Larry Seltzer  |  Posted 2006-11-02 Print this article Print

Many vendors also assert, as McAfee has publicly, that it will always be possible, perhaps even easy, to bypass PatchGuard and that therefore only the good guys get punished. Authentium even announced that it has "hacked" the system to bypass PatchGuard in order to implement products on it. Theres something to this, but not a whole lot. If a security mechanism had to be perfect in order to be implemented, wed all be in big trouble.

Certainly Microsoft never claimed that PatchGuard would be, to use another vendors term, "unbreakable." But the cracking angle has been greatly overblown. Its highly unlikely that any bypass of PatchGuard could be performed without already having administrator access. Vista already makes it much harder for malware to slip through on the administrator account.

Of course you need such access when you install security programs like Authentiums, but a security company would have to be insane to actually deploy a program that installs itself through a "hack" (to use the companys own characterization of the technique). The moment Microsoft patches the hack, any customers using the product will get blue screens they can blame squarely on Authentium. And PatchGuard has the potential to strengthen, perhaps with the assistance of processor-based virtualization technology.

Anyway, here we are, on the road to developing a solution to the problem. Before it comes out (in Vista SP1), the exposure is limited to certain protections for a relatively small segment of the marketplace. If the security vendors carry the day with their arguments then one of the consequences will be a slowing of adoption of 64-bit Windows. Im not sure whose interests that serves, but its not Microsofts.

The best argument Ive heard against PatchGuard generally is the zero-day argument. The day will come, as one vendor told me, when a threat will emerge that security products can defend against only with kernel patching. If vendors then have to wait months or longer for Microsoft to come out with new APIs then the threat will go unmitigated and customers will suffer. Im not sure this is a realistic scenario, but it smacks of defeatism in that it argues for a fundamentally less secure platform. It cant be the right argument.

So it seems fair to say that Microsoft was late in implementing support for legitimate security vendors to work around the restrictions of PatchGuard, but thats basically old news. What are they supposed to do now? Make the operating system less secure so that security companies can rush in to fill the gap?

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Those security vendors who question Microsofts motives in this matter should be careful about their stone throwing. One could easily contrive an argument that they are not so much afraid of Microsofts security products as of a future more secure Windows, one that doesnt have the same need for outside security products. Why else are these same companies busy buying up compliance management firms?

What does PatchGuard really break? It, along with other security advances in Vista, puts the first big crack in the security industrys business model. These ISVs will insist that they want Windows to be secure, but in the end they are ill-served by a truly secure Windows operating system. Lucky for them, unlucky for us, not every attack is controllable by Microsoft, but the tide is turning.

Security Center Editor Larry Seltzer has worked in and written about the computer industry since 1983. Check out eWEEK.coms for the latest security news, reviews and analysis. And for insights on security coverage around the Web, take a look at eWEEK.com Security Center Editor Larry Seltzers Weblog. More from Larry Seltzer

Larry Seltzer has been writing software for and English about computers ever since—,much to his own amazement—,he graduated from the University of Pennsylvania in 1983.

He was one of the authors of NPL and NPL-R, fourth-generation languages for microcomputers by the now-defunct DeskTop Software Corporation. (Larry is sad to find absolutely no hits on any of these +products on Google.) His work at Desktop Software included programming the UCSD p-System, a virtual machine-based operating system with portable binaries that pre-dated Java by more than 10 years.

For several years, he wrote corporate software for Mathematica Policy Research (they're still in business!) and Chase Econometrics (not so lucky) before being forcibly thrown into the consulting market. He bummed around the Philadelphia consulting and contract-programming scenes for a year or two before taking a job at NSTL (National Software Testing Labs) developing product tests and managing contract testing for the computer industry, governments and publication.

In 1991 Larry moved to Massachusetts to become Technical Director of PC Week Labs (now eWeek Labs). He moved within Ziff Davis to New York in 1994 to run testing at Windows Sources. In 1995, he became Technical Director for Internet product testing at PC Magazine and stayed there till 1998.

Since then, he has been writing for numerous other publications, including Fortune Small Business, Windows 2000 Magazine (now Windows and .NET Magazine), ZDNet and Sam Whitmore's Media Survey.

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