Mar  7 05:33:28 mail.srvfarm.net postfix/smtpd[2592865]: NOQUEUE: reject: RCPT from unknown[63.81.87.163]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar  7 05:35:19 mail.srvfarm.net postfix/smtpd[2588803]: NOQUEUE: reject: RCPT from unknown[63.81.87.163]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar  7 05:35:56 mail.srvfarm.net postfix/smtpd[2593187]: NOQUEUE: reject: RCPT from unknown[63.81.87.163]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar  7 05:37:04 mail.srvfarm.net postfix/smtpd[2594963]: NOQUEUE: reject: RCPT from unknown

Apr  4 15:20:30 mail.srvfarm.net postfix/smtpd[3301977]: NOQUEUE: reject: RCPT from unknown[63.81.87.144]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Apr  4 15:24:30 mail.srvfarm.net postfix/smtpd[3318077]: NOQUEUE: reject: RCPT from unknown[63.81.87.144]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Apr  4 15:25:55 mail.srvfarm.net postfix/smtpd[3314744]: NOQUEUE: reject: RCPT from unknown[63.81.87.144]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Apr  4 15:26:40 mail.srvfarm.net postfix/smtpd[3301977]: NOQUEUE: reject: RCPT from unknown[63.81.87.144]: 450 4.1.8 :

Apr  4 05:30:07 web01.agentur-b-2.de postfix/smtpd[920628]: NOQUEUE: reject: RCPT from unknown[63.81.87.178]: 450 4.7.1 : Helo command rejected: Host not found; from= to= proto=ESMTP helo=
Apr  4 05:30:13 web01.agentur-b-2.de postfix/smtpd[920628]: NOQUEUE: reject: RCPT from unknown[63.81.87.178]: 450 4.7.1 : Helo command rejected: Host not found; from= to= proto=ESMTP helo=
Apr  4 05:32:45 web01.agentur-b-2.de postfix/smtpd[920628]: NOQUEUE: reject: RCPT from unknown[63.81.87.178]: 450 4.7.1 : Helo command rejected: Host not found; from= to= proto=ESMTP helo=
Apr  4 05:33:38 web01.agentur-b-2.de postfix/smtpd[920628]: NOQUEUE: reject: RCPT from unknown[63.81.87.178]: 450 4.7.1 

(RCPT) RCPT NOT ALLOWED FROM  63.81.87.167 (US/United States/-): 1 in the last 3600 secs

Apr  2 05:35:44 mail.srvfarm.net postfix/smtpd[1755935]: NOQUEUE: reject: RCPT from unknown[63.81.87.146]: 554 5.7.1 Service unavailable; Client host [63.81.87.146] blocked using zen.spamhaus.org; https://www.spamhaus.org/sbl/query/SBLCSS; from= to= proto=ESMTP helo=
Apr  2 05:35:44 mail.srvfarm.net postfix/smtpd[1753858]: NOQUEUE: reject: RCPT from unknown[63.81.87.146]: 554 5.7.1 Service unavailable; Client host [63.81.87.146] blocked using zen.spamhaus.org; https://www.spamhaus.org/sbl/query/SBLCSS; from= to= proto=ESMTP helo=
Apr  2 05:35:45 mail.srvfarm.net postfix/smtpd[1755903]: NOQUEUE: reject: RCPT from unknown[63.81.87.146]: 554 5.7.1 Service unavailable; Client host [63.81.87.146] blocked using zen.spamhaus.org; https://www.spamhaus.org/sbl/query/SBLCSS; from= to= proto=ESMTP helo=

Apr  2 06:54:55 web01.agentur-b-2.de postfix/smtpd[72992]: NOQUEUE: reject: RCPT from unknown[63.81.87.151]: 450 4.7.1 : Helo command rejected: Host not found; from= to= proto=ESMTP helo=
Apr  2 06:54:55 web01.agentur-b-2.de postfix/smtpd[77755]: NOQUEUE: reject: RCPT from unknown[63.81.87.151]: 450 4.7.1 : Helo command rejected: Host not found; from= to= proto=ESMTP helo=
Apr  2 06:54:55 web01.agentur-b-2.de postfix/smtpd[77756]: NOQUEUE: reject: RCPT from unknown[63.81.87.151]: 450 4.7.1 : Helo command rejected: Host not found; from= to= proto=ESMTP helo=
Apr  2 06:54:55 web01.agentur-b-2.de postfix/smtpd[77758]: NOQUEUE: reject: RCPT from unknown[63.81.87.151]: 450 4.7.1 : Helo command rejected: Host not found; from=

Mar 31 23:29:39 mail.srvfarm.net postfix/smtpd[783722]: NOQUEUE: reject: RCPT from unknown[63.81.87.159]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 31 23:29:41 mail.srvfarm.net postfix/smtpd[783721]: NOQUEUE: reject: RCPT from unknown[63.81.87.159]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 31 23:30:28 mail.srvfarm.net postfix/smtpd[796986]: NOQUEUE: reject: RCPT from unknown[63.81.87.159]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 31 23:31:50 mail.srvfarm.net postfix/smtpd[778578]: NOQUEUE

Mar 30 05:24:03 tux postfix/smtpd[14066]: connect from unknown[63.81.87.157]
Mar x@x
Mar 30 05:24:04 tux postfix/smtpd[14066]: disconnect from unknown[63.81.87.157]


........
-----------------------------------------------
https://www.blocklist.de/en/view.html?ip=63.81.87.157

Mar 29 05:33:39 mail.srvfarm.net postfix/smtpd[755834]: NOQUEUE: reject: RCPT from unknown[63.81.87.146]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 29 05:35:33 mail.srvfarm.net postfix/smtpd[774356]: NOQUEUE: reject: RCPT from unknown[63.81.87.146]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 29 05:35:42 mail.srvfarm.net postfix/smtpd[755659]: NOQUEUE: reject: RCPT from unknown[63.81.87.146]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 29 05:37:35 mail.srvfarm.net postfix/smtpd[756001]: NOQUEU

Mar 22 05:36:09 mail.srvfarm.net postfix/smtpd[562348]: NOQUEUE: reject: RCPT from unknown[63.81.87.152]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 22 05:36:26 mail.srvfarm.net postfix/smtpd[562346]: NOQUEUE: reject: RCPT from unknown[63.81.87.152]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 22 05:37:58 mail.srvfarm.net postfix/smtpd[557306]: NOQUEUE: reject: RCPT from unknown[63.81.87.152]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 22 05:37:58 mail.srvfarm.net postfix/smtpd[561117]: NOQUEUE: reject: RCPT from unknown[63.81.87.152]: 450 4.1.8 : Sender address

Mar 20 05:34:59 mail.srvfarm.net postfix/smtpd[2604122]: NOQUEUE: reject: RCPT from unknown[63.81.87.179]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 20 05:34:59 mail.srvfarm.net postfix/smtpd[2603295]: NOQUEUE: reject: RCPT from unknown[63.81.87.179]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 20 05:35:05 mail.srvfarm.net postfix/smtpd[2603273]: NOQUEUE: reject: RCPT from unknown[63.81.87.179]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 20 05:35:07 mail.srvfarm.net postfix/smtpd[2588041]: NOQUEUE: reject: RCPT from unknown[63.81.87.179]: 450 4.1.8 

Mar 17 01:28:30 mail.srvfarm.net postfix/smtpd[575988]: NOQUEUE: reject: RCPT from unknown[63.81.87.170]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 17 01:28:33 mail.srvfarm.net postfix/smtpd[588708]: NOQUEUE: reject: RCPT from unknown[63.81.87.170]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 17 01:30:31 mail.srvfarm.net postfix/smtpd[588739]: NOQUEUE: reject: RCPT from unknown[63.81.87.170]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 17 01:30:32 mail.srvfarm.net postfix/smtpd[575986]: NOQUEUE: reject: RCPT from unknown[63.81.87.170]: 450 4.1.8 

Mar 16 16:25:31 mail.srvfarm.net postfix/smtpd[249206]: NOQUEUE: reject: RCPT from unknown[63.81.87.145]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 16 16:25:41 mail.srvfarm.net postfix/smtpd[249187]: NOQUEUE: reject: RCPT from unknown[63.81.87.145]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 16 16:26:04 mail.srvfarm.net postfix/smtpd[220455]: NOQUEUE: reject: RCPT from unknown[63.81.87.145]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 16 16:26:31 mail.srvfarm.net postfix/smtpd[249188]: NOQUEUE: reject: RCPT from unknown[63.81.87.145]: 450 4.1.8 

Mar 12 13:47:08 mail.srvfarm.net postfix/smtpd[1811060]: NOQUEUE: reject: RCPT from unknown[63.81.87.140]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 12 13:47:08 mail.srvfarm.net postfix/smtpd[1830689]: NOQUEUE: reject: RCPT from unknown[63.81.87.140]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 12 13:47:08 mail.srvfarm.net postfix/smtpd[1830650]: NOQUEUE: reject: RCPT from unknown[63.81.87.140]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 12 13:47:08 mail.srvfarm.net postfix/smtpd[1827922]: NOQUEUE: reject: RCPT from unknown[63.81.87.140]: 450 4.1.8 

Mar 12 04:41:19 mail.srvfarm.net postfix/smtpd[1642187]: NOQUEUE: reject: RCPT from unknown[63.81.87.174]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 12 04:41:24 mail.srvfarm.net postfix/smtpd[1636114]: NOQUEUE: reject: RCPT from unknown[63.81.87.174]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 12 04:41:48 mail.srvfarm.net postfix/smtpd[1642190]: NOQUEUE: reject: RCPT from unknown[63.81.87.174]: 450 4.1.8 : Sender address rejected: Domain not found; from= to= proto=ESMTP helo=
Mar 12 04:44:06 mail.srvfarm.net postfix/smtpd[1642190]: NOQUEUE: reject: RCPT from unknown[63.81.87.174]: 450 4.1.8 : Sender address rejected: Domain not found;

Mar 10 04:32:26 web01 postfix/smtpd[4013]: connect from unknown[63.81.87.142]
Mar 10 04:32:26 web01 policyd-spf[4019]: None; identhostnamey=helo; client-ip=63.81.87.142; helo=mature.svcoding.com; envelope-from=x@x
Mar 10 04:32:26 web01 policyd-spf[4019]: Pass; identhostnamey=mailfrom; client-ip=63.81.87.142; helo=mature.svcoding.com; envelope-from=x@x
Mar x@x
Mar 10 04:32:27 web01 postfix/smtpd[4013]: disconnect from unknown[63.81.87.142]
Mar 10 04:33:00 web01 postfix/smtpd[4013]: connect from unknown[63.81.87.142]
Mar 10 04:33:01 web01 policyd-spf[4019]: None; identhostnamey=helo; client-ip=63.81.87.142; helo=mature.svcoding.com; envelope-from=x@x
Mar 10 04:33:01 web01 policyd-spf[4019]: Pass; identhostnamey=mailfrom; client-ip=63.81.87.142; helo=mature.svcoding.com; envelope-from=x@x
Mar x@x
Mar 10 04:33:01 web01 postfix/smtpd[4013]: disconnect from unknown[63.81.87.142]
Mar 10 04:38:17 web01 postfix/smtpd[3383]: connect from unknown[63.81.87.142]
Mar 10 04:38:17 web0........
-------------------------------

URL Probing: /xmlrpc.php

Aug  5 03:46:04 game-panel sshd[8871]: Failed password for root from 49.232.5.230 port 41734 ssh2
Aug  5 03:51:00 game-panel sshd[9027]: Failed password for root from 49.232.5.230 port 49624 ssh2

Automated report (2020-08-05T05:55:00+02:00). Caught masquerading as Yandex/Яндекс.

Aug  5 07:07:03 nextcloud sshd\[16197\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=222.186.175.163  user=root
Aug  5 07:07:05 nextcloud sshd\[16197\]: Failed password for root from 222.186.175.163 port 45270 ssh2
Aug  5 07:07:16 nextcloud sshd\[16197\]: Failed password for root from 222.186.175.163 port 45270 ssh2

Dovecot Invalid User Login Attempt.

Aug  5 05:57:57 rocket sshd[7859]: Failed password for root from 71.45.233.98 port 46885 ssh2
Aug  5 06:02:17 rocket sshd[8510]: Failed password for root from 71.45.233.98 port 59985 ssh2
...

Tried our host z.

$f2bV_matches

Aug  5 06:51:11 dev0-dcde-rnet sshd[27182]: Failed password for root from 112.85.42.173 port 22354 ssh2
Aug  5 06:51:14 dev0-dcde-rnet sshd[27182]: Failed password for root from 112.85.42.173 port 22354 ssh2
Aug  5 06:51:17 dev0-dcde-rnet sshd[27182]: Failed password for root from 112.85.42.173 port 22354 ssh2
Aug  5 06:51:20 dev0-dcde-rnet sshd[27182]: Failed password for root from 112.85.42.173 port 22354 ssh2

Aug  5 06:51:24 debian-2gb-nbg1-2 kernel: \[18861546.559428\] \[UFW BLOCK\] IN=eth0 OUT= MAC=96:00:00:0e:18:f4:d2:74:7f:6e:37:e3:08:00 SRC=87.251.74.19 DST=195.201.40.59 LEN=40 TOS=0x00 PREC=0x00 TTL=245 ID=21152 PROTO=TCP SPT=45728 DPT=18080 WINDOW=1024 RES=0x00 SYN URGP=0

(sshd) Failed SSH login from 86.59.208.134 (HU/Hungary/563BD086.dsl.pool.telekom.hu): 5 in the last 3600 secs

*Port Scan* detected from 115.98.241.216 (IN/India/Maharashtra/Mumbai/-). 4 hits in the last 15 seconds

20/8/5@00:41:20: FAIL: Alarm-Network address from=113.168.19.63
...

SSH Brute-Forcing (server2)

216.10.245.49 - - [05/Aug/2020:04:55:27 +0100] "POST /wp-login.php HTTP/1.1" 200 1905 "-" "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:62.0) Gecko/20100101 Firefox/62.0"
216.10.245.49 - - [05/Aug/2020:04:55:28 +0100] "POST /wp-login.php HTTP/1.1" 200 1890 "-" "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:62.0) Gecko/20100101 Firefox/62.0"
216.10.245.49 - - [05/Aug/2020:04:55:31 +0100] "POST /wp-login.php HTTP/1.1" 200 1887 "-" "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:62.0) Gecko/20100101 Firefox/62.0"
...