$f2bV_matches

Mar  4 13:32:54 wbs sshd\[21035\]: Invalid user liuyukun from 210.71.232.236
Mar  4 13:32:54 wbs sshd\[21035\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=210-71-232-236.hinet-ip.hinet.net
Mar  4 13:32:56 wbs sshd\[21035\]: Failed password for invalid user liuyukun from 210.71.232.236 port 56674 ssh2
Mar  4 13:42:09 wbs sshd\[21944\]: Invalid user smbguest from 210.71.232.236
Mar  4 13:42:09 wbs sshd\[21944\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=210-71-232-236.hinet-ip.hinet.net

Mar  5 00:45:39 srv01 postfix/smtpd\[20960\]: warning: unknown\[45.133.99.130\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Mar  5 00:46:03 srv01 postfix/smtpd\[986\]: warning: unknown\[45.133.99.130\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Mar  5 00:47:16 srv01 postfix/smtpd\[986\]: warning: unknown\[45.133.99.130\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Mar  5 00:47:35 srv01 postfix/smtpd\[986\]: warning: unknown\[45.133.99.130\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Mar  5 00:50:44 srv01 postfix/smtpd\[20960\]: warning: unknown\[45.133.99.130\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
...

Mar  5 04:58:26 gw1 sshd[2117]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=106.124.137.108
Mar  5 04:58:29 gw1 sshd[2117]: Failed password for invalid user ubnt from 106.124.137.108 port 46285 ssh2
...

Mar  5 04:54:59 gw1 sshd[2012]: Failed password for irc from 180.76.243.116 port 50550 ssh2
...

Mar  5 00:49:04 debian-2gb-nbg1-2 kernel: \[5624916.885344\] \[UFW BLOCK\] IN=eth0 OUT= MAC=96:00:00:0e:18:f4:d2:74:7f:6e:37:e3:08:00 SRC=37.139.103.87 DST=195.201.40.59 LEN=40 TOS=0x00 PREC=0x00 TTL=242 ID=11586 PROTO=TCP SPT=50079 DPT=53302 WINDOW=1024 RES=0x00 SYN URGP=0

imap or smtp brute force

Mar  4 19:59:30 vps46666688 sshd[11400]: Failed password for lp from 31.207.34.147 port 57734 ssh2
...

Mar  4 18:45:10 debian sshd[28446]: Unable to negotiate with 45.33.70.146 port 59560: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group-exchange-sha256 [preauth]
Mar  4 18:45:10 debian sshd[28448]: Unable to negotiate with 45.33.70.146 port 32896: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group-exchange-sha256 [preauth]
...

Mar  5 00:57:56 nextcloud sshd\[24794\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=222.186.173.142  user=root
Mar  5 00:57:58 nextcloud sshd\[24794\]: Failed password for root from 222.186.173.142 port 63774 ssh2
Mar  5 00:58:01 nextcloud sshd\[24794\]: Failed password for root from 222.186.173.142 port 63774 ssh2

2020-03-04 15:51:44 H=(mail.office.gov35.ru) [91.207.5.10]:38922 I=[192.147.25.65]:25 F= rejected RCPT : Sender verify failed
2020-03-04 15:52:03 H=(mail.office.gov35.ru) [91.207.5.10]:39206 I=[192.147.25.65]:25 sender verify fail for : Unrouteable address
2020-03-04 15:52:03 H=(mail.office.gov35.ru) [91.207.5.10]:39206 I=[192.147.25.65]:25 F= rejected RCPT : Sender verify failed
...

until 2020-03-04T20:42:29+00:00, observations: 3, bad account names: 1

Mar  5 01:13:15 nextcloud sshd\[6905\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=222.186.175.183  user=root
Mar  5 01:13:16 nextcloud sshd\[6905\]: Failed password for root from 222.186.175.183 port 57874 ssh2
Mar  5 01:13:20 nextcloud sshd\[6905\]: Failed password for root from 222.186.175.183 port 57874 ssh2

Tried sshing with brute force.

Mar  5 05:36:53 areeb-Workstation sshd[4299]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=134.249.124.230 
Mar  5 05:36:55 areeb-Workstation sshd[4299]: Failed password for invalid user pms from 134.249.124.230 port 52676 ssh2
...