Image spam

[Stephen Swaney]

> -----Original Message-----
> From: mailscanner-bounces at lists.mailscanner.info [mailto:mailscanner-
> bounces at lists.mailscanner.info] On Behalf Of Chris Yuzik
> Sent: Wednesday, February 28, 2007 2:58 PM
> To: MailScanner discussion
> Subject: Re: Image spam
> 
> Renee Gehlbach wrote:
> > I see plenty of ham w/ attached gifs through one of my servers, but
> > very little from others.  Yet another example there being no one
> > standard pattern for ham.
> >
> > Hmm....  why exactly would this be preferable?  We tend to set email
> > clients not to permit the display non-attached images in html
> > messages.  Thunderbird and Squirrelmail, I believe, even do this by
> > default.  I've heard plenty of arguments against allowing email
> > clients to go retrieve pictures, do you have arguments for it?
> >
> > Do you use Fuzzy OCR?  It's the only way I've found to really target
> > image spam.
> Renee,
> 
> We are experimenting with Fuzzy OCR, and while in our tests it does
> catch some image spam, it's not doing very well with image spam where
> the image has background noise, slanted text, etc.
> 
> I agree that having a link to an external image is not (necessarily) a
> good idea, and in fact can activate web-bugs and such on spam that does
> manage to get through.
> 
> I find it interesting that Barracuda is advertising that they block
> "all
> image spam". Abaca is advertising they block 99% of all image spam. How
> are these guys achieving this success rate?
> 
> Chris

They're probably not :) I know that Barracuda has exaggerated performance
claims in the past. 

We're seeing almost no little image spam (none for the last week at least)
getting through without using FuzzOCR (too much load). How - Just
SpamAssassin with:

	SARE rule sets
	Milter-ahead (Snertsoft)
	Milter-link (Snertsoft)
	Razor
	DCC
	GreetPause
	Spamhaus (zen)

BTW For those who use them, Anthony Howe has new releases (today) of many of
his milters and the libsnert library now available at www.snertsoft.com

Steve

Steve Swaney
Fort Systems Ltd.
steve at fsl.com