Discovering and Stopping Phishing/Scam Attacks

[steven@lovebug.org]

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

[byte_jump]

I know of some financial institutions that have done this (for I
helped implement it) and it works quite well. They have proactively
shut down phishing sites while they were still in "test mode".

byte_jump

On 4/26/05, steven@lovebug.org <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.
>=20
> 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.
>=20
> 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 thei=
r
> 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 bac=
k
> 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.
>=20
> Just an idea -- let me know if anyone has any comments.
>=20
> Steven
> steven@lovebug.org
>=20
> -------------------------------------------------------------------------=
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>=20
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>=20
>

[Crispin Cowan]

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