Windows' Patchguard Hinders Security Vendors

eldavojohn writes "Windows' PatchGuard seems to be upsetting third party security vendors such as Symantec, Sana Security and Agnitum. It sounds like the 'black hats' will be able to bypass this security feature (which will be in all copies of Vista) but force security software companies to give up developing software for Windows. From the article: 'PatchGuard will make it harder for third parties, particularly host intrusion-prevention software, to function in Vista,' said Yankee Group analyst Andrew Jaquith. 'Third parties have two choices: continue to petition Microsoft to create an approved kernel-hooking interface so products like theirs can work, or use "black hat" techniques to bypass the restrictions.' Apparently, using these techniques is not a difficult trick."

Comments

Debugger Disables

[mugnyte]

It is fascinating that TFA explains how if a boot routine can initialize a "debugger attached" flag, the PatchGuard system is not initialized. From this aspect alone, I'd say MS should start playing more nicely with the vendors, since any malicious code worth it's salt should set this value permanently and then replace kernal routines on disk as necessary.

Also, given the fact that MS intends to making patching the standard for releasing a secure OS, the vendors can't really do this kernal checking themselves. Thus, I think it's safe to say from the perspective of this article, the OS's kernel is patchable by anyone.

Re:Why would microsoft bother?

[jd]

The obvious answer would be for Microsoft to define a well-known API for security software, where the entry-point for that set of functions is damn-near impervious. (A simple example - require that all software using such an API be digitally signed by a trusted vendor and counter-signed by the registered owner of the software. In a corporate setting, this would mean that patches would need to be signed off on by the IT department. In the home setting, users would have to specifically state that they approve that level of access for the software.)

Certificates of trust already exist in Windows. They're used by web browsers. It would be trivial to use the code that is already present to check for a valid certificate. The second layer of protection - requiring the user/IT department to countersign the patch - would make transparent breakins much harder. Not impossible, but definitely much harder.

Of course, this is all pointless these days, anyway. All a rootkit writer has to do is develop a mini hypervisor or hijack one already in use. For zombies, viruses, etc, you'd then have the externally-visible interfaces in the OS and everything else concealed outside. BIOS viruses could also be quite lethal, as they too would bypass this protection. Far too low a level for the OS to detect. These days, with graphics processors essentially being parallel CPUs, I'm surprised nobody has put a virus on the graphics card. If the PCI is multi-mastered (not uncommon on higher-end machines), then the card could control all the other devices without going through the OS at all, giving a virus that could inhabit that space ABSOLUTE power over the machine.