Giving Your Greytrapping a Helping Hand

Peter N. M. Hansteen writes "Some spam houses have invested in real mail servers now, meaning that they are able to get past greylisting and even content filtering. Recently Peter Hansteen found himself resorting to active greytrapping to put some spammers in their place. The article also contains a list of spam houses' snail mail addresses in case you want to tour their sites."

Comments

Grey-trapping

[goombah99]

I was not clear on the definition of grey-trapping. It is the process of providing decoy e-mail addresses that are discoverable by harvesters but not by ordinary humans. When mail arrives at the destination of a decoy, the sender IP address is then added to the spam filter of the receiver.

Basically sort of a honey pot approach.

So you might ask why can't ISPS do this at the ISP level rather than the user level? Make it opt-in, white-listable, etc..

The problem is what happens when some reputable sender get's on the list.

FOr example, Joe Spammer takes his address list and does a sing-up operation to Yahoo for all the addresses. Now the Yahoo registration server then does not automatically enroll them but still it sends an e-mail to every one of the e-mail addresses. some of which are the decoys.

so Yahoo gets grey-listed by the ISP.

I would think this attack would also foul up every grey-list in existance as well. So I don't actually understand how grey-listing works.

Yawn. Antispam is a commodity purchase now.

[CFD339]

At one time I invested a few weeks time into building a heuristic antispam filter. One of the principles I used was very similar to this (there were many others).

I came to the conclusion pretty quickly that in the game of anti-spam, the larger the email pool you have, the more efficient your heuristic tools can be. Once I proved that to myself, I went looking for who was doing the best job using the techniques I decided worked best, and routed my mail through them.

Its cheap, effective, and gets the spam off my network bandwidth. Even if you do a perfect job yourself, you're still paying for the traffic. That's a waste by itself.

If you're so worried about privacy, get yourself an appliance that uses the same principles as the services (like postini, etc.). Either way, antispam is no longer a business for the individual.