« previous next »
Pages: [1]

Author Topic: Fake users sending spam  (Read 4775 times)

0 Members and 2 Guests are viewing this topic.

Offline
leors
*
Fake users sending spam
« on: January 11, 2022, 02:40:26 PM »
On one server, I am facing problems with SPAM.
A few months ago, I noticed shots to unknown senders.
I mitigated the problem by blocking the recipient's domain.

Quote
Jan 11 08:47:53 cwp postfix/smtpd[18216]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 450 4.7.1 <recipient@random.tdl>: Recipient address rejected: 1; from=<non-existent-email@myserver.tdl> to=<recipient@random.tdl> proto=ESMTP helo=<myserver.tdl>

PHP's mail function is disabled.
I cannot detect the origin of these messages.
Logged
Offline
iraqiboy90
***
Re: Fake users sending spam
« Reply #1 on: January 11, 2022, 03:55:26 PM »
Can you post the lines above and below this single log-line...
Logged
Offline
leors
*
Re: Fake users sending spam
« Reply #2 on: January 11, 2022, 05:37:51 PM »
Quote from: leors on January 11, 2022, 05:37:08 PM
Jan 11 08:44:43 cwp postfix/smtpd[17250]: lost connection after RCPT from localhost[127.0.0.1]
Jan 11 08:44:43 cwp postfix/smtpd[17250]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 commands=2/3
Jan 11 08:44:43 cwp cbpolicyd[10726]: module=Quotas, action=defer, host=127.0.0.1, helo=myserver.tdl, from=collatedbg@myserver.tdl, to=b.lichtenberg@random.de, reason=quota_match, policy=6, quota=
3, limit=4, track=Sender:@myserver.tdl, counter=MessageCount, quota=11.58/10 (115.8%)
Jan 11 08:44:43 cwp postfix/smtpd[17251]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 450 4.7.1 <b.lichtenberg@random.de>: Recipient address rejected: 1; from=<collatedbg@myserver.tdl> to=<b.lichtenberg@random.de> proto=ESMTP helo=<myserver.tdl>
Jan 11 08:44:43 cwp postfix/smtpd[17251]: lost connection after RCPT from localhost[127.0.0.1]
Jan 11 08:44:43 cwp postfix/smtpd[17251]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 commands=2/3
Jan 11 08:44:43 cwp cbpolicyd[17260]: module=Quotas, action=defer, host=127.0.0.1, helo=myserver.tdl, from=f_ycqxcyirp@myserver.tdl, to=frank-rilling@random.de, reason=quota_match, policy=6, quota=3, limit=4, track=Sender:@myserver.tdl, counter=MessageCount, quota=11.58/10 (115.8%)
Jan 11 08:44:43 cwp postfix/smtpd[17258]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 450 4.7.1 <frank-rilling@random.de>: Recipient address rejected: 1; from=<f_ycqxcyirp@myserver.tdl> to=<frank-rilling@random.de> proto=ESMTP helo=<myserver.tdl>
Jan 11 08:44:43 cwp postfix/smtpd[17258]: lost connection after RCPT from localhost[127.0.0.1]
Jan 11 08:44:43 cwp postfix/smtpd[17258]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 commands=2/3
Jan 11 08:45:17 cwp postfix/smtpd[17254]: warning: hostname examsection.earacheevince.com does not resolve to address 212.192.246.26
Jan 11 08:45:17 cwp postfix/smtpd[17254]: connect from unknown[212.192.246.26]
Jan 11 08:45:20 cwp postfix/smtpd[17254]: warning: unknown[212.192.246.26]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Jan 11 08:45:20 cwp postfix/smtpd[17254]: lost connection after AUTH from unknown[212.192.246.26]
Jan 11 08:45:20 cwp postfix/smtpd[17254]: disconnect from unknown[212.192.246.26] ehlo=1 auth=0/1 commands=1/2
Jan 11 08:45:41 cwp postfix/smtpd[17224]: connect from unknown[85.202.169.215]
Jan 11 08:45:44 cwp postfix/smtpd[17224]: warning: unknown[85.202.169.215]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Jan 11 08:45:44 cwp postfix/smtpd[17224]: lost connection after AUTH from unknown[85.202.169.215]
Jan 11 08:45:44 cwp postfix/smtpd[17224]: disconnect from unknown[85.202.169.215] ehlo=1 auth=0/1 commands=1/2
Jan 11 08:45:57 cwp postfix/smtpd[17257]: connect from localhost[127.0.0.1]
Jan 11 08:45:57 cwp cbpolicyd[17233]: module=Quotas, action=defer, host=127.0.0.1, helo=myserver.tdl, from=falcon64se@myserver.tdl, to=jgrjr@random.com, reason=quota_match, policy=6, quota=3, limit=4, track=Sender:@myserver.tdl, counter=MessageCount, quota=11.36/10 (113.6%)
Jan 11 08:45:57 cwp postfix/smtpd[17257]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 450 4.7.1 <jgrjr@random.com>: Recipient address rejected: 1; from=<falcon64se@myserver.tdl> to=<jgrjr@random.com> proto=ESMTP helo=<myserver.tdl>
Jan 11 08:45:57 cwp postfix/smtpd[17257]: lost connection after RCPT from localhost[127.0.0.1]
Jan 11 08:45:57 cwp postfix/smtpd[17257]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 commands=2/3
Jan 11 08:45:57 cwp postfix/smtpd[17251]: connect from localhost[127.0.0.1]
Jan 11 08:45:57 cwp cbpolicyd[10726]: module=Quotas, action=defer, host=127.0.0.1, helo=myserver.tdl, from=equip@myserver.tdl, to=hardypark@random.com, reason=quota_match, policy=6, quota=3, limit=4, track=Sender:@myserver.tdl, counter=MessageCount, quota=11.36/10 (113.6%)
Jan 11 08:45:57 cwp postfix/smtpd[17251]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 450 4.7.1 <hardypark@random.com>: Recipient address rejected: 1; from=<equip@myserver.tdl> to=<hardypark@random.com> proto=ESMTP helo=<myserver.tdl>
Jan 11 08:45:57 cwp postfix/smtpd[17251]: lost connection after RCPT from localhost[127.0.0.1]
Jan 11 08:45:57 cwp postfix/smtpd[17251]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 commands=2/3
Jan 11 08:47:53 cwp postfix/smtpd[18216]: connect from localhost[127.0.0.1]
Jan 11 08:47:53 cwp cbpolicyd[21400]: module=Quotas, action=defer, host=127.0.0.1, helo=myserver.tdl, from=eor@myserver.tdl, to=bigdadztoyz@random.com, reason=quota_match, policy=6, quota=3, limit=4, track=Sender:@myserver.tdl, counter=MessageCount, quota=11.02/10 (110.2%)
Jan 11 08:47:53 cwp postfix/smtpd[18216]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 450 4.7.1 <bigdadztoyz@random.com>: Recipient address rejected: 1; from=<eor@myserver.tdl> to=<bigdadztoyz@random.com> proto=ESMTP helo=<myserver.tdl>
Jan 11 08:47:53 cwp postfix/smtpd[18216]: lost connection after RCPT from localhost[127.0.0.1]
Jan 11 08:47:53 cwp postfix/smtpd[18216]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 commands=2/3
Jan 11 08:48:28 cwp clamd[30013]: SelfCheck: Database status OK.
Logged
Offline
dp41646
*
Re: Fake users sending spam
« Reply #3 on: January 11, 2022, 09:12:44 PM »
I've had similar problem, a few weeks ago...
CWP team should investigate this, as this kind of spam can really make server IP address reputation bad...
Logged
Offline
studio4host
*
Re: Fake users sending spam
« Reply #4 on: January 11, 2022, 10:16:13 PM »
Logged
VPS & Dedicated server provider with included FREE Managed support for CWP.
http://www.studio4host.com/

*** Don't allow that your server or website is down, choose hosting provider with included expert managed support for your CWP.
Offline
Netino
***
Re: Fake users sending spam
« Reply #5 on: January 11, 2022, 11:47:30 PM »
Quote from: leors on January 11, 2022, 05:37:51 PM
(...)
Jan 11 08:44:43 cwp postfix/smtpd[17250]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 commands=2/3
Jan 11 08:44:43 cwp cbpolicyd[10726]: module=Quotas, action=defer, host=127.0.0.1, helo=myserver.tdl, from=collatedbg@myserver.tdl, to=b.lichtenberg@random.de, reason=quota_match, policy=6, quota=
3, limit=4, track=Sender:@myserver.tdl, counter=MessageCount, quota=11.58/10 (115.8%)
Jan 11 08:44:43 cwp postfix/smtpd[17251]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 450 4.7.1 <b.lichtenberg@random.de>: Recipient address rejected: 1; from=<collatedbg@myserver.tdl> to=<b.lichtenberg@random.de> proto=ESMTP helo=<myserver.tdl>
Jan 11 08:44:43 cwp postfix/smtpd[17251]: lost connection after RCPT from localhost[127.0.0.1]
Jan 11 08:44:43 cwp postfix/smtpd[17251]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 commands=2/3
Jan 11 08:44:43 cwp cbpolicyd[17260]: module=Quotas, action=defer, host=127.0.0.1, helo=myserver.tdl, from=f_ycqxcyirp@myserver.tdl, to=frank-rilling@random.de, reason=quota_match, policy=6, quota=3, limit=4, track=Sender:@myserver.tdl, counter=MessageCount, quota=11.58/10 (115.8%)
Jan 11 08:44:43 cwp postfix/smtpd[17258]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 450 4.7.1 <frank-rilling@random.de>: Recipient address rejected: 1; from=<f_ycqxcyirp@myserver.tdl> to=<frank-rilling@random.de> proto=ESMTP helo=<myserver.tdl>
Jan 11 08:44:43 cwp postfix/smtpd[17258]: lost connection after RCPT from localhost[127.0.0.1]
Jan 11 08:44:43 cwp postfix/smtpd[17258]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 commands=2/3
Jan 11 08:45:17 cwp postfix/smtpd[17254]: warning: hostname examsection.earacheevince.com does not resolve to address 212.192.246.26
Jan 11 08:45:17 cwp postfix/smtpd[17254]: connect from unknown[212.192.246.26]
Jan 11 08:45:20 cwp postfix/smtpd[17254]: warning: unknown[212.192.246.26]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Jan 11 08:45:20 cwp postfix/smtpd[17254]: lost connection after AUTH from unknown[212.192.246.26]
Jan 11 08:45:20 cwp postfix/smtpd[17254]: disconnect from unknown[212.192.246.26] ehlo=1 auth=0/1 commands=1/2
(...)

The spam is coming from localhost. It doesn't appear to be an open relay. It looks like some script on the server itself is allowing this sending attempt. The web logs for the same time and/or spam start time should be investigated to try to identify which scripts are allowing this.
The following files/directories must be scanned:
/usr/local/apache/logs/
/usr/local/apache/domlogs/
/usr/local/cwpsrv/var/services/roundcube/logs/
Logged
Offline
dani521
*
Re: Fake users sending spam
« Reply #6 on: January 12, 2022, 03:16:19 PM »
i`am experiencing the same problem from last week again from localhost the clamav doesn`t find malware ?
Logged
Offline
iraqiboy90
***
Re: Fake users sending spam
« Reply #7 on: January 12, 2022, 06:26:22 PM »
Quote from: Netino on January 11, 2022, 11:47:30 PM
The spam is coming from localhost. It doesn't appear to be an open relay. It looks like some script on the server itself is allowing this sending attempt. The web logs for the same time and/or spam start time should be investigated to try to identify which scripts are allowing this.
The following files/directories must be scanned:
/usr/local/apache/logs/
/usr/local/apache/domlogs/
/usr/local/cwpsrv/var/services/roundcube/logs/

my thought exactly. Since php mail is disabled, you will have to go the route of "process of elimination".
Btw, make sure mail in php is diabled by confirming that it's disabled everywhere:
Check "disable_functions = mail"
PHP-FPM- /opt/alt/php-fpm**/usr/php/php.ini
PHP-CGI- /opt/alt/php**/usr/php/php.ini
PHP-Main- /usr/local/php/php.ini
PHP-CWP- /usr/local/cwp/php71/php.ini <-- [Not sure if webpanel mail will break if disabled here]

Another measure is to put this in main.cf file:
Code: [Select]
smtpd_sender_restrictions =
        permit_mynetworks,
        permit_sasl_authenticated,
        reject_non_fqdn_sender,
        reject_unknown_sender_domain

and to make it more strict, is to change the order of the first two lines, but the server won't be able to send mail without authentication:
Code: [Select]
smtpd_sender_restrictions =
        permit_sasl_authenticated,
        permit_mynetworks,
        reject_non_fqdn_sender,
        reject_unknown_sender_domain
« Last Edit: January 12, 2022, 06:32:41 PM by iraqiboy90 »
Logged
Pages: [1]
« previous next »