[38638] in bugtraq

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Re: Discovering and Stopping Phishing/Scam Attacks

daemon@ATHENA.MIT.EDU (Crispin Cowan)
Wed Apr 27 20:15:34 2005

Message-ID: <426EC7D2.1050504@immunix.com>
Date: Tue, 26 Apr 2005 15:59:30 -0700
From: Crispin Cowan <crispin@immunix.com>
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To: steven@lovebug.org
Cc: incidents@securityfocus.com, bugtraq@securityfocus.com
In-Reply-To: <1312.128.173.146.141.1114545545.spork@webmail.lovebug.org>
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I think that this will just force the phishers to host their own images. 
As such, this approach is not very interesting unless there actually is 
a problem for the phishers in hosting their own images. The phishers 
could even host their own images on virtual domains that are typo-alike 
to the legitimate domain name.

For me personally, I would not notice the difference, as I already have 
my mail client configured to not load referenced images, because 
spammers already use hits on their hosted images as web bugs to detect 
working e-mails, and that just brings more spam down on your head. If 
you are loading images referenced in e-mails, you probably want to 
figure out how to turn that off.

Crispin

steven@lovebug.org wrote:

>As we have all noticed, there has increase in the number of phishing/scam
>attempts via e-mail that appear to be legitimate.  Most of
>these e-mails look identical to e-mails that would be sent by the
>e-commerce or banking institute.  They also frequently link to
>fraudulent/hacked webservers that also appear very similar to the website
>they are masquerading as.
>
>I noticed quite some time ago is that most of these websites
>and e-mails do not host their own images.  From what I have seen, more
>often than not, these e-mails and websites link directly to images hosted
>by the legitimate website.  For example, I just received an eBay scam
>asking me to signup to be a PowerSeller.  The PowerSeller artwork, logos,
>and other images are all linked directly from eBay.  So this makes me
>realize that there are a few things some of these targeted
>websites/businesses can do to detect these scam sites much quicker.  I
>have made this suggestion to a few banking institutions in the past, and I
>have no idea if anyone has actually decided to implement my ideas or not
>-- but they seem pretty feasible.
>
>Since they are linking to the images hosted on the site they are cloning
>-- the banking/e-commerce website could just rename their images on
>their own webpage every so often (and update their webpages accordingly). 
>However, at the same time they should keep copies of the images with their
>old names.  Now they can check their logs to see what webpage(s) are
>accessing these old image names.  Chances are they will link directly back
>to the hacked website purporting to be their page.  This would allow for
>quicker detection of this phishing and scam websites, providing a slight
>leg up for sites trying to fight this.
>
>Just an idea -- let me know if anyone has any comments.
>
>Steven
>steven@lovebug.org
>
>  
>

-- 
Crispin Cowan, Ph.D.  http://immunix.com/~crispin/
CTO, Immunix          http://immunix.com


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