Graphic Based Spams

James Gray james at grayonline.id.au
Wed Mar 9 21:23:01 GMT 2005


    [ The following text is in the "utf-8" character set. ]
    [ Your display is set for the "US-ASCII" character set.  ]
    [ Some characters may be displayed incorrectly. ]

On Thu, 10 Mar 2005 07:45 am, Michael Baird wrote:
> Heh guys, this may not be a problem directly related to MailScanner, but
> I'm having issues with spams that are just graphics (Viagra Cheap), they
> score very low and make it through. What is the best way to handle these
> types of spam, tweak the spamassassin scores a bit? Update to the latest
> spamassassin? Just looking for advice on the subject.
>
> Regards
> Michael Baird

I have a few "RAWBODY" rules that look for MIME boundaries that describe
embedded graphics.  They score around the 0.9 mark.  Then I have some other
RAWBODY rules that look for the first few bytes (in BASE64) of each of the
graphics.  I've found these spammers send the *same* embedded GIF with a
picture of 4 pills - the graphic is identical making the BASE64 detection
easy :)  I've also increased the score of some of the standard SA rules
which catch base64 encoded content too.

Have a look at raw message and grab the strings that match what you're
seeing.  Alternatively, post a copy of the message on a website somewhere
and I can grok it for you and post back here the rules I derive from it :)

Cheers,

James
--
An effective way to deal with predators is to taste terrible.

------------------------ MailScanner list ------------------------
To unsubscribe, email jiscmail at jiscmail.ac.uk with the words:
'leave mailscanner' in the body of the email.
Before posting, read the MAQ (http://www.mailscanner.biz/maq/) and
the archives (http://www.jiscmail.ac.uk/lists/mailscanner.html).

Support MailScanner development - buy the book off the website!




More information about the MailScanner mailing list