Date: Sat, 24 Nov 2012 20:25:30 +0200 From: Alexander Yerenkow <yerenkow@gmail.com> To: trafdev <trafdev@mail.ru> Cc: freebsd-hackers@freebsd.org Subject: Re: postfix mail server infected ? Message-ID: <CAPJF9wm-88LkPLx4GkJGnxdNoMHG6G6v15cO=CqUPTm-joKYSg@mail.gmail.com> In-Reply-To: <50B10D10.80209@mail.ru> References: <50B10D10.80209@mail.ru>
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Would be better if you include pkg info / pkg_info output, as well `who`, and try to monitor and record via netstat all programs trying to connect to 25 port. Also, what portaudit telling you? Regards, Alexander Yerenkow 24.11.2012 20:08 =D0=CF=CC=D8=DA=CF=D7=C1=D4=C5=CC=D8 "trafdev" <trafdev@ma= il.ru> =CE=C1=D0=C9=D3=C1=CC: > Hi. I've a dedicated stand-alone FreeBSD server: > > uname -a > FreeBSD trafd-website-freebsd 9.0-RELEASE-p3 FreeBSD 9.0-RELEASE-p3 #0: > Tue Jun 12 02:52:29 UTC 2012 root@amd64-builder.**daemonology.net: > /usr/obj/usr/**src/sys/GENERIC amd64 > > Server has one external interface (re0) with IP 206.239.112.241 and > postfix service installed on 25 port. > > Yesterday I've noticed huge amount of emails sending out: > > Nov 24 00:00:37 trafd-website-freebsd postfix/smtpd[37230]: connect from > f116.sd.com[206.239.112.241] > Nov 24 00:00:37 trafd-website-freebsd postfix/qmgr[40324]: 73F7D1365D: > from=3D<wkktxh@f116.sd.com>, size=3D1211, nrcpt=3D10 (queue active) > Nov 24 00:00:37 trafd-website-freebsd postfix/error[37366]: 75ECA134F2: > to=3D<reco.motos@yahoo.com.br>, relay=3Dnone, delay=3D25715, > delays=3D25715/0.02/0/0.12, dsn=3D4.7.0, status=3Ddeferred (delivery temp= orarily > suspended: host mta7.am0.yahoodns.net[66.94.**236.34] refused to talk to > me: 421 4.7.0 [TS01] Messages from 206.239.112.241 temporarily deferred d= ue > to user complaints - 4.16.55.1; see http://postmaster.yahoo.com/** > 421-ts01.html <http://postmaster.yahoo.com/421-ts01.html>) > Nov 24 00:00:37 trafd-website-freebsd postfix/error[37368]: 794A911711: > to=3D<tayd@yahoo.com.br>, relay=3Dnone, delay=3D29716, > delays=3D29716/0.05/0/0.05, dsn=3D4.7.0, status=3Ddeferred (delivery temp= orarily > suspended: host mta7.am0.yahoodns.net[66.94.**236.34] refused to talk to > me: 421 4.7.0 [TS01] Messages from 206.239.112.241 temporarily deferred d= ue > to user complaints - 4.16.55.1; see http://postmaster.yahoo.com/** > 421-ts01.html <http://postmaster.yahoo.com/421-ts01.html>) > Nov 24 00:00:37 trafd-website-freebsd postfix/smtp[36699]: E559512F49: to= =3D< > luziarodrigues757@terra.**com.br <luziarodrigues757@terra.com.br>>, relay= =3D > vip-us-br-mx.terra.com[**208.84.244.133]:25, delay=3D26077, > delays=3D26075/1/0.59/0.31, dsn=3D4.7.1, status=3Ddeferred (host > vip-us-br-mx.terra.com[208.84.**244.133] said: 450 4.7.1 You've exceeded > your sending limit to this domain. (in reply to end of DATA command)) > Nov 24 00:00:37 trafd-website-freebsd postfix/error[37370]: 7C45D18E5D: > to=3D<a925er@yahoo.com.br>, relay=3Dnone, delay=3D6984, > delays=3D6984/0.02/0/0.04, dsn=3D4.7.0, status=3Ddeferred (delivery tempo= rarily > suspended: host mta7.am0.yahoodns.net[66.94.**236.34] refused to talk to > me: 421 4.7.0 [TS01] Messages from 206.239.112.241 temporarily deferred d= ue > to user complaints - 4.16.55.1; see http://postmaster.yahoo.com/** > 421-ts01.html <http://postmaster.yahoo.com/421-ts01.html>) > Nov 24 00:00:37 trafd-website-freebsd postfix/qmgr[40324]: 73E8118E53: > from=3D<t9zir@f116.sd.com>, size=3D1143, nrcpt=3D10 (queue active) > Nov 24 00:00:37 trafd-website-freebsd postfix/smtpd[37153]: 93E1020413: > client=3Df116.sd.com[206.239.**112.241] > Nov 24 00:00:37 trafd-website-freebsd postfix/error[37367]: 74A511A5BF: > to=3D<duscherer1@yahoo.com.br>, relay=3Dnone, delay=3D5587, > delays=3D5587/0/0/0.18, dsn=3D4.7.0, status=3Ddeferred (delivery temporar= ily > suspended: host mta7.am0.yahoodns.net[66.94.**236.34] refused to talk to > me: 421 4.7.0 [TS01] Messages from 206.239.112.241 temporarily deferred d= ue > to user complaints - 4.16.55.1; see http://postmaster.yahoo.com/** > 421-ts01.html <http://postmaster.yahoo.com/421-ts01.html>) > Nov 24 00:00:37 trafd-website-freebsd postfix/smtp[36698]: E7898134D0: to= =3D< > gvfg@terra.com.br>, relay=3Dvip-us-br-mx.terra.com[**208.84.244.133]:25, > conn_use=3D4, delay=3D25728, delays=3D25726/1.1/0.06/0.4, dsn=3D4.7.1, > status=3Ddeferred (host vip-us-br-mx.terra.com[208.84.**244.133] said: 45= 0 > 4.7.1 You've exceeded your sending limit to this domain. (in reply to end > of DATA command)) > Nov 24 00:00:37 trafd-website-freebsd postfix/smtp[36226]: 7BE421F989: to= =3D< > elc.moura@bol.com.br>, relay=3Dmx3.bol.com.br[200.147.**36.13]:25, > delay=3D339, delays=3D339/0/0.49/0.24, dsn=3D4.7.1, status=3Ddeferred (ho= st > mx3.bol.com.br[200.147.36.13] said: 450 4.7.1 <elc.moura@bol.com.br>: > Recipient address rejected: MX-BOL-04 - Too many messages, try again late= r. > (in reply to RCPT TO command)) > > Where f116.sd.com[206.239.112.241] is an IP and host assigned for > external interface (re0). > > Due to "permit_mynetworks" policy enabled in postfix conf mail was sendin= g > out without authentication. However all externally connected clients were > rejected which is proper and expected behavior: > > Nov 24 19:31:04 trafd-website-freebsd postfix/smtpd[65618]: connect from > a2-starfury4.uol.com.br[200.**147.33.227] > Nov 24 19:31:05 trafd-website-freebsd postfix/smtpd[65618]: NOQUEUE: > reject: RCPT from a2-starfury4.uol.com.br[200.**147.33.227]: 550 5.1.1 < > pehw@f116.sd.com>: Recipient address rejected: User unknown in virtual > mailbox table; from=3D<> to=3D<pehw@f116.sd.com> proto=3DESMTP helo=3D< > mx.uol.com.br> > Nov 24 19:31:05 trafd-website-freebsd postfix/smtpd[65618]: disconnect > from a2-starfury4.uol.com.br[200.**147.33.227] > > Then, I've tried: > > $cmd 001 deny all from any to me dst-port 25 in via re0 > $cmd 002 deny all from any to me dst-port 25 out via re0 > > and cleaned local mail queue with > postsuper -d ALL > > This didn't changed anything - server continued to send huge amount of > emails. > > However restrictions on lo0: > $cmd 001 deny all from any to me dst-port 25 in via lo0 > $cmd 002 deny all from any to me dst-port 25 out via lo0 > > did the trick - emailing had stopped. So by fact - problem solved, but th= e > real reason wasn't not found. > > I've launched clamav and f-prot scans - nothing suspicious found. > > The main question I have - how it's possible on stand-alone dedicated > server - who and how is connecting on behalf of it's own ext ip and uses > local interface to send emails? Is this possible to do from outside, or > server was infected from inside? > > ______________________________**_________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/**mailman/listinfo/freebsd-**hackers<http://list= s.freebsd.org/mailman/listinfo/freebsd-hackers> > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@** > freebsd.org <freebsd-hackers-unsubscribe@freebsd.org>" >
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