Penetration Testing mailing list archives

RE: USB delivered attacks - lessons learned/summary (so far)


From: "Jerry Shenk" <jshenk () decommunications com>
Date: Wed, 2 Jun 2004 14:25:09 -0400

NO.  At least not in my testing.  I didn't try multiple versions and
multiple service packs s there could be times when it does but in my
testing, when a CD was inserted with the screensaver locked, it never
ran autorun unless the CD was re-inserted after unlocking the screen.

-----Original Message-----
From: Jon McClintock [mailto:jammer () weak org] 
Sent: Wednesday, June 02, 2004 2:20 PM
To: Jerry Shenk
Subject: Re: USB delivered attacks - lessons learned/summary (so far)


Hi there,

Question on the autorun and screensavers...if I drop a CD in your
screensaver-locked desktop, does the autorun kick in when you unlock
the screensaver?

-Jon

On Tue, Jun 01, 2004 at 10:18:29PM -0400, Jerry Shenk wrote:
Well, I'm doing messing with this....at least for the moment.  Here's
what I've found out.  All my testing so far has been done on a Windows
XP laptop.  I was planning to try other versions  but for now, I'll
leave it go at this.  Here's a summaryy of what I've discovered:

USB devices don't use autorun - well, they seem to do something with
it
'cuz if there's an "open=" statement in the autorun.inf, they don't
pop
up an explorer window.  If there is an "icon=" statement in the
autorun.inf file, the icon for the explorer windows will be the
specified icon.  This leads me to believe that autorun is at least
looking at the USB drive.  Maybe if the right stuff is in that file,
there might be a way to run something.  I tried pulling the .ico file
off my web server but that didn't work...yet;)

Autorun under XP doesn't work if the screensaver has the screen
locked.
I didn't try this with multiple OS'.

The USB devices I tried were a flashdrive and an SD card reader with a
128 meg card from my camera.  I didn't try my 120 gig USB hard drive
'cuz it's formatted for the wrong OS at the moment....that kindof
blows
the clandestine nature of a thumbdrive....need for power, a rather
large
device....

Somebody said that 2600 had something about this type of thing in the
current 2600 magazine.  That would suggest that a few other people
have
been playing with this idea.  Somebody with more brains, ideas or time
than I is likely to come up with something pretty nasty.

Nearly every post stated something about the dangers of autorun.  One
post suggested just using a CD.  Most people have autorun turned on so
if there's an internet connection or a computer in the office that can
receive data....well, that'll work just as well as USB.  If the CD is
labeled with something "interesting", perhaps a few people will check
it
out.

Another poster suggested that this is all just a good reminder of the
basics of security, you wouldn't let some stranger come up and swap
drives in your machine, why assume that his USB thumbdrive is so
innocuous just 'cuz it's small and trendy.

Here's the autorun.inf file I was playing with
[autorun]
;OPEN=ping.exe 10.1.1.5
icon=http://www.website.org/blue.ico
;icon=\icons\red.ico


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