procmail
[Top] [All Lists]

Re: Concern: Anti-emailbomb recipe

1996-08-23 22:47:01
On Fri, 23 Aug 1996, athar shiraz siddiqui wrote:


I would be very interested in such a recipe as well. 
I have an algorithm for defense against mail bombing but as I am newly 
exposed to procmail I cannot code it.

This is the one that I put together after posting about it here (thanks 
to all who helped, BTW).  It will go through and dump any messages that 
aren't on maillists that you already subscribe to, and it will keep the 
welcome messages that usually have unsubscribe info in them.  The only 
problem with it is that you can rarely put the info for all the people 
who might be writing to you into the recipe, so a message or two will 
probably get lost when you use it.

# noflood - email bomb blocker
:0
* ! ^From:.*(postmaster|Mailer|listproc|majordomo|listserv)
# this line will keep the recipe from deleting Subscribe messages
* ! ^TO(mailing|lists|and|addresses|of|people|you|know|go|here)
/dev/null


Concept: The bomber can use (1) mailing lists or (2) he can use a script 
to send you say a thousand messages in a day. We have a solution ( prob. 
code too ) for (1) . 
But for (2).. we could 
(A) Log the senders and ban the account that sends more than say 10 
messgs. in one hour or one day .Or better begin counter measures ....like 
bouncing back mail and sending all man pages.

Hmm...I suppose that (A) might be possible, but I don't have the slightest 
idea how to do it.  

(B) Also we could check the size of the Inbox and remove excess mail, as 
it comes in, because if the bomber is a fellow procmail usr he can easily 
fake the FROM: field.

As I understand it, Procmail deals with the messages *before* they get to 
your mailbox, so removing the mail after it has been delivered would 
probably require doing it manually.  The key is to take care of it before 
it reaches your inbox.

I think B is more feasible and less taxing. 
is there a way of doing this ?


A. Shiraz Siddiqui


---

Zach Babayco

zachb(_at_)netcom(_dot_)com  <----- finger for PGP public key
http://www.geocities.com/SiliconValley/Park/4127



<Prev in Thread] Current Thread [Next in Thread>