[CentOS] Sendmail SMTP Brute-Force Attack

Thu Jun 14 23:33:23 UTC 2012
Gustavo Lacoste <gustavo at lacosox.org>

Dear CentOS Community

Is totally clear there's no support sendmail platform today, but I need  to
stop SMTP brute-force attack on sendmail. My server is attacked today, my
maillog look like :

4624 at myserver.com>, proto=ESMTP, daemon=MTA, relay=myserver.com []
Jun 14 19:07:01 at6412 sendmail[24627]: q5EN71jC024627: from=<>, size=3958,
class=0, nrcpts=1, msgid=<201206142307.q5EN710u024623 at myserver.com>,
proto=ESMTP, daemon=MTA, relay=myserver.com []
Jun 14 19:07:23 at6412 sendmail[24868]: q5EN7M6D024868: from=<
qmarket at qmarket.cl>, size=2193, class=0, nrcpts=2, msgid=<
20120614231448.1E99A13EE5F at smtp02qmarket.qmarket.cl>, proto=ESMTP,
daemon=MTA, relay=[]
Jun 14 19:07:24 at6412 sendmail[24961]: q5EN7OT4024961: from=<
nobody at 2012.123icq.cl>, size=4716, class=0, nrcpts=1, msgid=<
E1SfJ8H-0005kv-JE at 2012.123icq.cl>, proto=ESMTP, daemon=MTA, relay=
pc1.globalmac.cl [] (may be forged)
Jun 14 19:07:33 at6412 sendmail[25013]: q5EN7SqK025013: from=<
a.pfsvtij at yahoo.com>, size=760, class=0, nrcpts=1, msgid=<
1531549-634033-36 at owfzdl.net>, proto=SMTP, daemon=MTA, relay=
h095159149119.ys.dsl.sakhalin.ru []
Jun 14 19:07:37 at6412 sendmail[25065]: q5EN7bCj025065: from=<
en.viaimport at gmail.com>, size=4531, class=0, nrcpts=0, proto=ESMTP,
daemon=MTA, relay=186-105-73-29.baf.movistar.cl []

I need help for STOP this spamers right now.

Thanks in advance to anyone who can guide me

With Kind Regards,

     Gustavo A. Lacoste Z.
     Curacautín - Chile
     Skype: knxroot
     Msn & Gtalk: knx.root [at] gmail.com
     Home page: http://www.lacosox.org
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