Full Disclosure mailing list archives

Re: FW: Are consumers being misled by "phishing"?


From: "Chris Umphress" <umphress () gmail com>
Date: Fri, 30 Jun 2006 02:07:43 -0700

On 6/29/06, Josh L. Perrymon <joshuaperrymon () gmail com> wrote:

 Most companies believe that blocking HTML in email handicaps emails
effectiveness.. ( screw the newsletters.. put it on a website )

Hehe, agree with you there.

 Network Protection:
 I believe that it's possible to develop "widgets" to alert on this type of
directed phishing attacks. First you have to have the ability to monitor all
emails traffic. This shouldn't piss off legal because all users should have
already signed off on this.

MmmHmm. Enter 1984.

 The most effective would be to monitor all known public email addresses.
Including "planted' email address placed in forums and webpages to be
harvested. This would provide a greater % that traffic sent to those
addresses are directed attacks.. (Like an Email Honeypot :)

Planted e-mail addresses is an old idea. And so are e-mail honeypots.

Link: http://wiki.apache.org/spamassassin/ReportingMboxesToRazor

I also found a forum recently (sorry, don't remember the link) where
somebody took the IP address of visitors to his site and encrypted it
into a unique e-mail address so that he could learn the IPs of spam
bots.

 It should be easy to develop an analysis to pick up on standard phishing
emails. You would look for Anchors / links with IP addresses that resolve
outside of the "known- whiteliested" address list. This should at least
alert and place the email in a second level queue for analysis. You could
also do some type of grep on the email link looking for company X verbiage.

So... anything that doesn't match the whitelist gets tested against
the blacklist? :)

Having a more strict filter for users who aren't in the user's address
book is (IMO) one of the best ways, but that relies more on the end
user than on the company's sys admin.

 M$ Phishing filter may even be USEFUL ( Almost.... )

 So using the methods above you would have a system to alert on potential
phishing attacks scanning all emails or preferably only public emails
included "planted" ones.

 The widget performs analysis to determine if the email is a phishing
attack.

Thunderbird does some analysis in this area already. It's probably
closely related to the junk filters, but the phishing mails generally
find their way to the Junk or Trash folder before being opened on this
end, so I don't know a lot about it.

 This process could be automated to perform the whois so on…  So now we
should have determined the IP or block for the hosted phishing site.  We can
use something like M$ phishing filter. Send it the new whitelisted IP
address of the phishing site and the browser should block the site. If the
widget monitors all emails coming into the company then it should have the
ability to do some trending of who received certain emails.. sorted on
subjects for instance. One you found the phishing email you would have a
known list of all email addresses that received the email once the attack
has been spotted.

Performing thousands of WHOIS lookups per day for a medium-sized
business might be a little pricey for the purpose. There are tools
(like SpamAssassin) to filter out spam messages -- Even commercial
programs, but from what I hear, none of them is at 100% efficiency.
Hey, AOL is even charging to be on their "white list."

"The widget" might be useful for companies where all e-mail is only
accessible from a web interface (and e-mail can be deleted from the
local mbox file later), but generally you don't argue with the CEO
when he says he wants to use XYZ e-mail client while he is travelling.
Some of the employees, or worse, management, will see these e-mail
messages on occasion. This means that there would either have to be a
delayed delivery system for incoming e-mail, or the e-mail clients
will have to have an understanding of phishing -- and if that were the
case, then "the widget" should have caught it anyway. The user still
has to be educated.

My solution is simple. We have deer season, rabbit season, and tourist
season. Start a spammer season!

--
Chris Umphress <http://daga.dyndns.org/>

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