Ed Reed wrote:

> http://news.yahoo.com/s/ap/20070419/ap_on_hi_te/hackers_state_department
> This article describes a Trojan horse attack introduced via MS Office
> (Word) documents that provided remote access by adversaries to
> compromised systems.  It doesn't say if the exploit - "design flaw" -
> was intentionally introduced (a product of deliberate subversion) or
> not.  ...

Well, odds are not, given the source of the software in question (and, 
no, I don't mean that I think MS has much better security screening of 
its employees...  8-) ).

> ...  While the article may provide "comfort" to the "defense in depth"
> crowd (the State department THINKS the issue was discovered immediately
> - but then again, after they were made aware of it - so they knew what
> to watch for - they found numerous other compromised systems, so I
> wonder how many haven't (yet) been caught).


> This isn't terribly surprising, but it brings to mind a new insight (for
> me, anyway) into the issue that government and commercial customers are
> facing.
> We've (Aesec) been saying that subversion (deliberately introduced
> design and implementation defects into a customer's IT supply chain) is
> the preferred avenue of attack of professional adversaries, and I agree
> that it is.
> We've (Aesec) also noted that the commercial security industry is
> largely focused, instead, on discovering and patching software defects
> that can be easily discovered (via fuzzing and testing) and exploited to
> gain access to systems.
> Both those two avenues can lead to serious security breeches.
> But it's not necessary to plant an operative into a vendor's shop in a
> position to introduce flaws into software to gain advantage.  Simply
> knowing enough about the internal design and implementation of the
> system is likely to provide the adversary with the knowledge and
> opportunity to discover paths of attack that can be researched at their
> leisure, held until needed as what would be considered a private "zero
> day exploit".
> So at one end of the spectrum of malicious attacks are pure opportunists
> (including amateurs and script kiddies) using defects discovered through
> fuzzing interfaces and related black box testing techniques.  At the
> other end of the scale are paid professional operatives infiltrating
> vendor development and delivery supply chains to introduce defects
> intentionally.  And in the middle are those with "gray box" knowledge of
> products involved, who are in a better position than the public to
> identify attack vectors worth investigating.
> This middle ground would seem to significantly increase the threat -
> there are many more jobs in vendor organizations (and their supply and
> support chains) that provide privileged insight to product design,
> development, implementation and delivery than there are with direct code
> modification roles in the product.  So I think you'd have to assume that
> the pool of unreported zero day exploits may be much larger than
> generally expected.

I agree with all this, but...

You -- and all journalistic and other commentaries I've seen/heard on 
the increasingly common use of these targetted Office exploits -- miss 
one very important option, I think; the attacker has access to 
(partial) source of the closed, supposedly closely-held, proprietary 
software in question.

Recall the rumours and stories from a few years back of the MS source-
code thefts?  From memory, reputedly (most of) Win2K, some of WinXP (?) 
and (parts of) Office were stolen.  Parts of these thefts were clearly 
confirmed with (parts of) Windows OS source becoming downloadable from 
various "underground" sources sometime later.

Further, and more speculative, was the suggestion that the reputed 
(earlier) MS break-in (as opposed to the third-party licensee from 
which the OS source code was reputedly "clearly" obtained) was a 
Russian or Chinese hacker/hacking group.

Some say that there were multiple break-ins at MS around that time and 
that both Russian and Chinese groups were involved.

Nowadays most of the publicly discussed/disclosed targetted Office 
exploits have been attributed to Chinese-based "attackers".

Also of some interest might be the fact that it seems (at least to me) 
if there are version specificities in the exploits used in these 
targetted attacks, these more commonly restrict the applicability of 
the exploit to the older Office product versions.  Now, this may be 
indicative of overall improvements in MS code standards due to SDLC 
(are newer versions of Office distilled through SDLC?) and compiler 
"security" improvements, but it might also be indicative of the 
"attackers" (or, at least those they buy their exploits from) having 
access to the reputed/rumoured stolen Office source which, if it ever 
was stolen, would be code of older versions of Office and thus be more 
likely to have changed, and thus not exhibit the same vulnerabilities, 
in newer versions.

> Just a thought.



Nick FitzGerald

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