Thursday, January 18, 2007

where do stealthkit detectors belong

mike rothman brought up an interesting point today in a section of his daily incite - where does stealthkit (rootkit to those of you drinking the revisionist rootkit koolaid) belong? inside a larger security application suite (or perhaps a larger security application period) or on it's own as a separate tool? although they're often separate right now, mike thinks they probably shouldn't be...

but given how they operate and how best the fundamental technique they employ can be used, is merging them into larger products really reasonable?

most stealthkit detectors employ a generic detection technique known as a cross-view diff or cross-view analysis where essentially you look at some area of the computer in 2 or more different ways and see if there are any discrepancies between them... although most stealthkit detectors are trying to cut this particular corner, outside-the-box analysis is ultimately necessary to truly see through persistent stealthed malware... the av industry knew this back in the 90's (it was called clean booting back then, though microsoft has since recycled that term) but got microsoft's boot up their ass when NTFS became mainstream without any robust method to perform outside-the-box analysis on that type of file system so they've been squeaking by with safe-mode ever since... anti-spyware and other anti-malware apps that grew up in the interim have never even dealt with this methodology because active stealth went out of fashion for a number of years but for an anti-malware that deals specifically with stealth in a generic sort of way at least part of it's operation really should be done outside-the-box and that is going to set it apart from other anti-malware functionality...

as yet the only detector i know of that does an outside-the-box cross-view diff is the WinPE implementation of microsoft's strider ghostbuster rootkit detection technology but that's still just a research project... no one else does it because as yet microsoft have not made WinPE easily available to the public (though i've heard rumors this may change with vista) and the alternative, BartPE, must be generated by the user (due to copyright and licensing restrictions from microsoft) rather than distributed with the stealthkit detector, which is a not-so-simple task from the perspective of average-joe computer users...

but if the anti-stealthkit folks were to do things right, how well would the resulting product (that runs off a bootable cd) fit in with existing security apps? not very well would be my guess... it would be nice if anti-virus and other anti-malware apps could operate in a similar outside-the-box environment since stealth is just a means to hide what eventually becomes known-malware, but that defies centralized management consoles and scheduled scans and a variety of other convenience features (bloat) that they've accumulated over the years... outside-the-box is fundamentally at odds with convenience but it's necessary for reliable generic detection of stealthed objects so how can you reconcile stealth malware detection with the increasingly convenient unified anti-malware product?

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