Has my mail server been compromised (used as an open relay)?

Altiris · 10-09-2015, 08:42 PM

I just checked my maillogs and have noticed some strange activity. What appears to be that the account apache from my domain name is trying to send e-mail to a domain owned by yahoo that I own...or it may be the other way around as the log is confusing. The other thing is I see the words relay and a domain backpagedupree@gmail.com Here is some of the /var/log/maillog It also seems that the Apache user is trying to make an email directory but can't?

Code:

Oct  8 10:34:59 necc-data postfix/qmgr[1499]: 06431881485: from=<apache@dataglobe.net>, size=2043, nrcpt=1 (queue active)
Oct  8 10:34:59 necc-data amavis[1600]: (01600-14) ZNEJ2jxLcFH6 FWD from <apache@dataglobe.net> -> <backpagedupree@gmail.com>, BODY=7BIT 250 2.0.0 from MTA(smtp:[127.0.0.1]:10025): 250 2.0.$
Oct  8 10:34:59 necc-data amavis[1600]: (01600-14) Passed CLEAN {RelayedOpenRelay}, [127.0.0.1] <apache@dataglobe.net> -> <backpagedupree@gmail.com>, Message-ID: <20151008143457.8E475881479$
Oct  8 10:34:59 necc-data postfix/lmtp[30855]: 8E475881479: to=<backpagedupree@gmail.com>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.5, delays=0.05/0/0/1.5, dsn=2.0.0, status=sent (250 2.0.$
Oct  8 10:34:59 necc-data postfix/qmgr[1499]: 8E475881479: removed
Oct  8 10:34:59 necc-data postfix/smtp[30863]: BD95C881426: to=<MYYAHOOHERE@yahoo.com>, relay=mta6.am0.yahoodns.net[66.196.118.240]:25, delay=0.44, delays=0.03/0/0.22/0.18, dsn=5.7.9, status=$
Oct  8 10:34:59 necc-data postfix/cleanup[30851]: 54FDD881487: message-id=<20151008143459.54FDD881487@mail.dataglobe.net>
Oct  8 10:34:59 necc-data postfix/bounce[30865]: BD95C881426: sender non-delivery notification: 54FDD881487
Oct  8 10:34:59 necc-data postfix/qmgr[1499]: 54FDD881487: from=<>, size=4179, nrcpt=1 (queue active)
Oct  8 10:34:59 necc-data postfix/qmgr[1499]: BD95C881426: removed
Oct  8 10:34:59 necc-data postfix/local[30866]: warning: maildir access problem for UID/GID=80/80: create maildir file /srv/httpd/Maildir/tmp/1444314899.P30866.necc-data: Permission denied
Oct  8 10:34:59 necc-data postfix/local[30866]: warning: perhaps you need to create the maildirs in advance
Oct  8 10:34:59 necc-data postfix/local[30866]: 54FDD881487: to=<apache@dataglobe.net>, relay=local, delay=0.06, delays=0.03/0/0/0.03, dsn=5.2.0, status=bounced (maildir delivery failed: cr$
Oct  8 10:34:59 necc-data postfix/qmgr[1499]: 54FDD881487: removed
Oct  8 10:34:59 necc-data postfix/smtp[30864]: 06431881485: host gmail-smtp-in.l.google.com[74.125.22.27] said: 450-4.2.1 The user you are trying to contact is receiving mail at a rate that$
Oct  8 10:34:59 necc-data postfix/smtp[30864]: connect to gmail-smtp-in.l.google.com[2607:f8b0:400d:c06::1a]:25: Network is unreachable
Oct  8 10:35:02 necc-data postfix/smtp[30864]: 06431881485: to=<backpagedupree@gmail.com>, relay=alt1.gmail-smtp-in.l.google.com[64.233.190.27]:25, delay=3.8, delays=0.03/0/3.4/0.39, dsn=4.$
Oct  8 10:37:54 necc-data postfix/smtpd[30880]: connect from unknown[109.254.1.242]

EDIT: One thing just crossed my mind, I have Simple Machine Fourms running on this same machine. I have it set it up so that I have to accept users who sign up in order to be registered. Could it be that Apache user is trying to create a maildirectory for these messages?

Keruskerfuerst · 10-10-2015, 01:29 AM

Oct 8 10:37:54 necc-data postfix/smtpd[30880]: connect from unknown[109.254.1.242]

Try to find out, what adress belongs to this IP adress.

Didier Spaier · 10-10-2015, 04:54 AM

Quote:

Originally Posted by Keruskerfuerst

Oct 8 10:37:54 necc-data postfix/smtpd[30880]: connect from unknown[109.254.1.242]

Try to find out, what adress belongs to this IP adress.

Code:

~$ curl ipinfo.io/109.254.1.242
{
  "ip": "109.254.1.242",
  "hostname": "No Hostname",
  "city": "Donetsk",
  "region": "Donets'ka Oblast'",
  "country": "UA",
  "loc": "47.9917,37.7759",
  "org": "AS20590 Donbass Electronic Communications Ltd."
}~$

Keruskerfuerst · 10-10-2015, 07:07 AM

This cant be trough.

Does France have a interior intelligence?

Emerson · 10-10-2015, 07:12 AM

You can use online tools to check if your server is an open relay, one is here.

Altiris · 10-11-2015, 12:09 PM

Quote:

Originally Posted by Keruskerfuerst

This cant be trough.

Does France have a interior intelligence?

What? I don't even understand your sentence. Trough? True?

Quote:

Originally Posted by Emerson

You can use online tools to check if your server is an open relay, one is here.

Thanks, I tested mine and it said it wasn't an open relay. Phew.

kikinovak · 10-11-2015, 04:03 PM

I'm using Postfix as mail server (YMMV). In Postfix' configuration, there's one crucial option to specify:

Code:

...
mydomain       = dedibox.fr
mydestination  = sd-25854.dedibox.fr, localhost.localdomain, localhost
mynetworks     = 127.0.0.0/8
relayhost      =
...

Here, mynetworks specifies those networks that accept messages without authentication. The only one you can trust is yourself. Define anything other than localhost, and your mail server turns into what administrators here in France call "une pompe a merde" (I'll let you guess).

Cheers,

Niki