RE: Microsoft GhostBuster Opinions

["Todd Towles" <toddtowles () brookshires com>]

Dave wrote:

>     About Tripwire, I understand what it does.  It basically 
> runs a file integrity check on certain files and reports the 
> differences from the last (hopefully known good) scan.  Say 
> that Tripwire is running on a system that's been compromised 
> by a rootkit that's been designed to evade file integrity 
> checkers such as tripwire.  Since the rootkit has control of 
> the kernel it has control of all the low level functions, 
> like returning a file when asked for one.  So one way to 
> evade tripwire would be to return the real file when asked 
> for it in read-only mode and return the rootkit file when 
> asked for it in execution mode.  That way tripwire won't 
> think the file has changed, since it's being given the same 
> file as it checked before, but when the file is executed then 
> it's the malicious file.

But could this not be bypassed by running Tripwire from a bootable CD?
The modified keneral would be inactive and therefore you would see the
two separate files are opposed to just one. This is the idea that this
new Microsoft products uses, but as people have stated, this can be done
now with a combination of open-source products.

-Todd
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