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Date:      Tue, 03 Apr 2012 23:51:01 +1000
From:      Da Rock <freebsd-questions@herveybayaustralia.com.au>
To:        freebsd-questions@freebsd.org
Subject:   Re: Printer recommendation please
Message-ID:  <4F7B0045.2050809@herveybayaustralia.com.au>
In-Reply-To: <20120403153039.55a7f5d5.freebsd@edvax.de>
References:  <4F75D37C.2020203@lovetemple.net> <20120330232307.41e420b1.freebsd@edvax.de> <4f7770b7.BkVKquuSmumStBb/%perryh@pluto.rain.com> <20120401112923.47e6c8a7.freebsd@edvax.de> <4f79c113.4NFuCWPOnCnPln6u%perryh@pluto.rain.com> <20120402073303.1ae0ea96@scorpio> <4f7b3fe0.PWM597T4KrLqJxhq%perryh@pluto.rain.com> <20120403084005.576af98e@scorpio> <20120403153039.55a7f5d5.freebsd@edvax.de>

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On 04/03/12 23:30, Polytropon wrote:
> On Tue, 3 Apr 2012 08:40:05 -0400, Jerry wrote:
>> On a serous note, I have spent the last 12 hours, more or less,
>> checking with my friends and business associates. Not a single one has
>> ever had or knows of a single incident of anyone actually ever being
>> infected or having suffered any negative reaction to having printed a
>> PDF file. Most, but not all of these friends / associates are Microsoft
>> users; however, that should not invalidate the statistics.
> That might be a problem: Malicious acts take place in the
> background. The time where a virus would pop a "funny message"
> on the screen are long over. In "Windows" land, there are
> limited resources for means of diagnostics and troubleshooting.
> Many people believe (and please take that word seriously)
> that they "have no virus", and if you bring a laptop with
> a traffic scanner (e. g. Wireshark, ex Ethereal), you can
> see scary things happen on their network. In worst case,
> the police rushes in, takes all the PCs, and the sloppy
> explaination they give is: "We're investigating a case of
> copyright infringement, we suspect your PCs being an active
> sharepoint of copyrighted material." While "Windows" and
> its programs presents lots of bells&  whistles to the user,
> there's no real chance to find out what's _really_ happening
> behind that curtain.
>
> There are _tons_ of programs out there that can be considered
> "snake oil" in regards of security. "Windows" users know 'em,
> many of them use 'em. I can imagine if PDF printers spread
> more and more, they become more interesting to attackers, and
> malware like "Professional Printer Anti-Malware Check XXL Super
> High Security Programs" will spread, waiting for the poor-minded
> victims to run them, and BANG! printer pwn'd. This is the _first_
> step into turning a corporate network into a botnet. If the
> attacker is able to "hide inside" a printer, it's much easier
> for him to do "sniper attacks" with precision as he is in
> control of a full-featured networking devices that nobody
> recognizes... or verifies. Running virus scans, malware scans
> and so on on "Windows" PCs has become standard by the majority
> of its users. Printers are not concerned here, and maybe there
> are no proper tools available to do the pending tests.

No. A traffic sniffer would be required to intercept traffic and 
discover any abnormalities. Most sysadmins wouldn't pay much attention, 
but you can bet it _will_ require a printer technician with training on 
the model to fix it- firmware usually requires either passworded telnet 
access or similar, possibly in conjunction with service software only 
available to the dealer- and may provide yet a whole new market for 
office machine service. I'd say sysadmins would expect the manufacturer 
to actually handle this issue.
>
> Applying that consideration to PDF files, virus scanners
> would have to check them before they are sent to the printer.
>
>
>
>> In fact, the
>> FOSS society claims MS is more vulnerable to infections/hijacking
>> then they are.
> This is due to its usage share. I believe if Linux (for example)
> would run on 90% of home PCs, attackers would concentrate
> their activities on that platform. Given the statement that
> the platform is more secure in a technical way (by design and
> implementation), attackers would potentially try to access the
> weakest part: the user. This kind of attack is different from
> those that work in a technical way (e. g. overwriting a printer's
> firmware silently and secretly), because it does not depend on
> technical vulnerabilities in the first place.
>
> FOSS or not, people have to understand that security is not
> a static thing, it's a process that involves _them_ to act.
> A Linux server with telnet enabled and empty root password
> is as dangerous as a "Windows" PC in a corporate network.
>
> Now there's something interesting "hidden": Let's say a malicious
> file is sent to the printer to compromise it. It's send from
> a Linux workstation. Will Linux (to keep this example) have
> to contain a kind of "PDF virus scanner" by default? Take
> into mind what I said about "behind the curtain". When a printer
> is compromised, and it acts maliciously within a Linux environment
> that is poorly secured, I agree with your statement that using
> a FOSS system does not imply security per se.
>
Having found a poorly 'written' pdf, I believe a simple pdf2pdf (using 
gs with similar commands as pdf2ps) will be sufficient to 'clean' the 
pdf file- or render it harmless. But essentially running through the 
cups filters (speaking of the general user) will do this I think- easily 
verified.

Incidentally the pdf was written using MS Office, which offers yet 
another can o' worms.
>
>> The original PDF code was written years ago. Since about 2006 hackers
>> have started finding vulnerabilities in it.
> That's a well-known fact in IT security. As I said, it's up
> to the manufacturers to properly deal with the security issues
> as good as possible. If they _can_ remove certain attack vectors
> for example by ignoring specific sections of PDF data, it would
> be a benefit for security without actually reducing functionality.
> It starts beginning complicated if there is a feature that is
> needed which can be used _against_ the system. Maybe data
> validation can help here...
>
>
>
>> There was one that attacked
>> scanned documents in MS Office. That problems was fixed over two years
>> ago. Virtually all PDF attacks now target Web Browsers. A case can be
>> made that viewing PDF files in a Web Browser is far more likely to
>> infect a machine than printing such document ever could.
> Yes, that approach is welcome to attackers as it allows them
> to take over a full-featured "Windows" PC within seconds - the
> user just has to visit a certain web page. By "auto-open magic"
> of certain MUAs it's even easier to accomplish.
>
> Attacking a printer, however, is much more silent. Why?
> Because nobody CARES. Printers are not in the scope of
> security. Does anyone imagine to run a virus check on a
> printer? Does the firmware have the latest manufacturer
> patches? Is there a password in the administration interface?
> What traffic is running across the printer? While many sysadmins
> (even in MICROS~1 environments) are aware of checking and
> cleaning (and reinstalling) the "Windows" PCs frequently,
> the things "hidden" in the printer are often left out. So
> right after cleaning the PCs, the network could be "re-initialized"
> by an attacker who "lives inside" the printer.
>
> After all, I think social engineering based attacks will become
> much more popular than addressing printers. I do _not_ say to
> keep ignorant and carry on, but there are higher threats than
> the PDF-capable laser printer in room 101. :-)
>
>
>




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