Re: Strange WLAN behavior

[Adam Mooz <adam.mooz () gmail com>]

Sounds like someone's doing something malicious.  There was a tool announced at Shmoocon, Airdrop-NG which could be 
used to deauth all targets except this one malicious node.  This forces users to look for a working AP, and find an 
open, free, public wifi...how convienent right?  Or join the next AP with the same SSID, and since Windows doesn't 
check anything beyond the SSID (i.e. does it have the same security settings as the legit AP) it will connect by 
deafult.  This is slightly tangential to your problem but something to consider.  

If you can look at this in kismet I'm going to assume you can also put your wifi card into promiscious, or monitor 
mode.  If you can, fire up Wireshark and look for deauthentication packets (or any other strange behavior), if you see 
a slew of them, or only deauth packets when your wife's laptop goes to join your network, then someone's actively 
trying to steal your data.  It sounds like you're in an apartment, compact-housing, or other form of high-density 
living which are prime targets for blackhatters, skiddies, or people just looking to otherwise ruin your day.  

Don't login to anything sensitive until you're 100% positive what's going on with this network, I'd even consider 
switching to a wired connection.

-----------------------------------------------------------------
Adam Mooz
Adam.Mooz () gmail com
http://www.AdamMooz.com

On 2010-03-30, at 2:58 PM, Jon Janego wrote:

> It sounds like yes, someone is impersonating the AP that you normally
> connect to.
>
> As far as next steps, it depends on your goal - to find the guy, or to
> eliminate the problem your wife is having?  If you're just interested
> in stopping your immediate problems, change the SSID of your home AP,
> and then clean out the wireless connections list in your wife's PC.
> By default, Windows XP will probe for all the access points you've set
> up and you want to remove any reference to the "hijacked" AP.
>
> If you're trying to kill the offending AP, on the other hand, you have
> a few options.  You could purchase a second AP and essentially get in
> a signal-DOS war - broadcasting from another AP with the power cranked
> up and a high beacon rate; this should effectively prevent others from
> connecting to it.  Or use a dedicated laptop and send continuous
> deauthentication messages to the clients connected to the AP, which
> will prevent people from using it.
>
> You can also go on a warwalk using a directional antenna and kismet
> (and a GPS if you want to plot it on a map), and try and find the
> offending AP and unplug it (or confront the owner).
>
> If it was up to me, I'd first try and stop the problem from affecting
> my machines - by changing your home SSID, and clearing references to
> the old name - and then go on a hunt to identify where it's coming
> from.  Getting into deauth or DOS attacks is a bit morally/legally
> grey and ultimately unsustainable.
>
>
> On Tue, Mar 30, 2010 at 8:37 AM, Norealenemy <norealenemy () web de> wrote:
> > Hello out there,
> >
> > since a couple of days my wife complained her bad wireless connection.
> > She said that the System (XP) often disconnects and sometimes the
> > connect messages says "connected to MyWLAN(insecure)" The WLAN is WPA2
> > protected using a very log PW including special characters.
> >
> > So yesterday I had some time to play with her laptop and was wondering
> > as I saw that her system told me to be connected to "MyWLAN" with 54
> > MBits on the router she was connected with 48 MBits.
> >
> > I started kismet on my laptop and was sniffing the air on my channel.
> > First thing I was wondering, was that MyWLAN has 7 (up to 9) Clients,
> > but the most strange thing was, that when I was generating traffic on
> > her laptop I saw the packet count growing on her and an absolute unknown
> > MAC address. The packet count stops on both addresses and starts again
> > growing when I start the ping (or anything else generating traffic)
> > again.
> >
> > Does that mean that my wifes laptop connects to an attacker AP, that is
> > forwarding her packets?
> >
> > - How can I find out who it is?
> > - What would you do next?
> > - Is there a way to prevent such attacks?
> >
> >
> > Thanks in advance Jensemann
> >
> > --
> >
> >           ,  ,                 __.   .  .
> > .    ,._.*-+--+-_ ._    _ ._   (__  _.|_ | _ ._ ._ *
> >  \/\/ [  | |  |(/,[ )  (_)[ )  .__)(_.[ )|(/,[_)[_)|
> >                                             |  |
> >  _, _, ,  _,    _, _,    _, _,   , ._,  _, _,  _, _,
> > '_)|.|/| |.|___|.|'_)___'_)|.|  /| |_ *'_)'_)*'_)'_)
> > /_.|_|.|.|_|   |_|._)   ._)|_|  .|.._)*/_./_.*/_./_.
> >
> >
> >
> > ------------------------------------------------------------------------
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> In this guide we examine the importance of Apache-SSL and who needs an SSL certificate.  We look at how SSL works, 
> how it benefits your company and how your customers can tell if a site is secure. You will find out how to test, 
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> ------------------------------------------------------------------------

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