Message-ID: <v02130500ac9ebece09cc@[196.20.20.2]> Date: Mon, 9 Oct 1995 13:11:34 +0100 From: Dr Eberhard W Lisse <mailto:el@LISSE.NA> Subject: Re: Recent spammers To: Multiple recipients of list DEVEL-L <mailto:DEVEL-L@AMERICAN.EDU>
At 1:12 10.9.1995, Chip Temm wrote: [...] >The point: is it time to change DEVEL-L's security level to preclude the
>possibility of future spams? We don't seem to get many (valid) posts from
>non-subscribers. Couldn't the list be set to refuse messages from
>non-members?
You don't understand how a spam works:
A perl script takes a .newsrc files which has all newsgroup on a system and fires off a message to all groups in the file. There is nothing you can do against this. They can easily change the subsject to something inconspicous.
Now what one can do is running a program called cancelbot or cancelmoose which looks for posts by a certain user to numerous newsgroups and once it finds one it issues a control message to the news system cancelling these messages. They will still be transported but the cancel messages are in close pursuit and usually become efective on any target system, before a human reads the message.
Now however this does not work on lists such as this one which is gatewayed to and from the news system. The message leaves the news system so to say when it reaches the list (which is email based) so that the cancelbot can't do anyhting about it. This happens quite often in fact so the people reading the list as news often don't even see the offending message.
I have suggested, several times, a way proposed by John Quaterman to block this.
What you do is to make the email list only take messages from subscribers. People reading it from the news must then suspend the mail messages but still remain on the list. Then you make the newsgroup moderated. However you set up mailto:DEVEL-L@AMERICAN.EDU as the moderator of the news group. DEVEL-L@AMERICAN.EDU in itself remains unmoderated. This means that any posting to the news group is sent to the moderator, which in turn is the mailto:DEVEL-L@AMERICAN.EDU list, which checks if the poster is subscribed, and if it is the case accepts the message. Because it is gatewayed to the news system, the message appears on the news group and on the list but only people subscribed can post. Now you don't want to restrict subscriptions (which you also can do) but the spam will not work.
All this squealing and whining is preaching to the converted...
el
-- Dr. Eberhard W. Lisse \ / Swakopmund State Hospital mailto:<el@lisse.NA> * | Resident Medical Officer Private Bag 5004 \ / 641 61503 (pager) 641 5550 (home) Swakopmund, Namibia ;____/ Postmaster Namibia <mailto:postmaster@lisse.NA>