[OT] HELP!!! mail attack
Rodolfo Alcazar Portillo
rodolfo.alcazar at padep.org.bo
Wed Mar 26 15:22:35 UTC 2008
Am Mittwoch, den 26.03.2008, 05:12 -0700 schrieb Craig White:
> That account has likely been 'Joe Jobbed' and you are seeing the
> backscatter. Google 'Joe Job' or find it on Wikipedia for an
> explanation.
Great. Seems precisely the problem.
> My first 'defense' is greylisting, run as a policy in postfix.
The same, I have greylistings activated sometime ago. Works great.
Except for bounces, which usually come from real and valid servers.
> My second defense is to use rbl's (abuseat / spamhaus / dsbl) to
> otherwise block KNOWN blacklisted sources
Already activated.
> My third defense is to require:
> - reverse DNS of sender
> - fqdn of sender
> - valid hostname
> - valid recipient
Ok. I will try these.
> Once I have accepted e-mail, it is shuffled to 'MailScanner' which is a
> wrapper program that sends e-mail through clamav and then through
> spamassassin, where it is cleaned and scored.
I have the same. The problem is that I received so many mails to that
account, until /var/spool/mqueue.in became flooded.
> Finally, I have 'sieve' rules for all users which puts high spam score
> e-mails into a users 'SPAMBOX' folder of which everything that is older
> than 7 days is automatically cleaned out.
Thanks a lot, you gave us a lot of lights on how to approach the
problem. We are working on finding a pattern to filter the emails, but
until now, nothing. You can see the word* files from a lot of messages
here (trying to find IPs and so on):
http://www.padep.org.bo/log20080325/log/
:)
----------------------------------------------
Rodolfo Alcazar - rodolfo.alcazar at padep.org.bo
otbits.blogspot.com / counter.li.org: #367962
----------------------------------------------
"Solange Menschen denken, dass Tiere nicht fühlen; müssen Tiere fühlen,
dass Menschen nicht denken."
- Unbekannter Autor
More information about the users
mailing list