May  7 06:57:36 server sshd[36143]: Failed password for invalid user teamspeak from 179.221.72.99 port 56370 ssh2
May  7 07:03:50 server sshd[41353]: Failed password for invalid user chenrongyan from 179.221.72.99 port 34226 ssh2
May  7 07:10:09 server sshd[46183]: User www-data from 179.221.72.99 not allowed because not listed in AllowUsers

May  7 07:39:11 srv-ubuntu-dev3 sshd[72090]: Invalid user kannel from 148.77.14.106
May  7 07:39:11 srv-ubuntu-dev3 sshd[72090]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=148.77.14.106
May  7 07:39:11 srv-ubuntu-dev3 sshd[72090]: Invalid user kannel from 148.77.14.106
May  7 07:39:12 srv-ubuntu-dev3 sshd[72090]: Failed password for invalid user kannel from 148.77.14.106 port 27066 ssh2
May  7 07:42:55 srv-ubuntu-dev3 sshd[72697]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=148.77.14.106  user=root
May  7 07:42:57 srv-ubuntu-dev3 sshd[72697]: Failed password for root from 148.77.14.106 port 58510 ssh2
May  7 07:46:40 srv-ubuntu-dev3 sshd[73363]: Invalid user admin from 148.77.14.106
May  7 07:46:40 srv-ubuntu-dev3 sshd[73363]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=148.77.14.106
May  7 07:46:40 srv-ubuntu-dev3 sshd[73363]: Invalid user admin from 148
...

MY_APNIC-HM_<177>1588823754 [1:2403498:57082] ET CINS Active Threat Intelligence Poor Reputation IP TCP group 100 [Classification: Misc Attack] [Priority: 2]:  {TCP} 103.234.100.38:11177

May  6 03:24:48 vayu sshd[713511]: Address 222.253.33.14 maps to static.vnpt.vn, but this does not map back to the address - POSSIBLE BREAK-IN ATTEMPT!
May  6 03:24:48 vayu sshd[713511]: Invalid user stuser from 222.253.33.14
May  6 03:24:48 vayu sshd[713511]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=222.253.33.14 
May  6 03:24:51 vayu sshd[713511]: Failed password for invalid user stuser from 222.253.33.14 port 49983 ssh2
May  6 03:24:51 vayu sshd[713511]: Received disconnect from 222.253.33.14: 11: Bye Bye [preauth]
May  6 03:29:18 vayu sshd[715232]: Address 222.253.33.14 maps to static.vnpt.vn, but this does not map back to the address - POSSIBLE BREAK-IN ATTEMPT!
May  6 03:29:18 vayu sshd[715232]: Invalid user qin from 222.253.33.14
May  6 03:29:18 vayu sshd[715232]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=222.253.33.14 


........
-----------------------------------------------
https://www.blocklist.de/en/view.

May  7 07:50:55 buvik sshd[18231]: Failed password for root from 120.53.27.233 port 33090 ssh2
May  7 07:53:44 buvik sshd[18536]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=120.53.27.233  user=root
May  7 07:53:46 buvik sshd[18536]: Failed password for root from 120.53.27.233 port 38112 ssh2
...

May  7 07:10:52 debian-2gb-nbg1-2 kernel: \[11087139.312231\] \[UFW BLOCK\] IN=eth0 OUT= MAC=96:00:00:0e:18:f4:d2:74:7f:6e:37:e3:08:00 SRC=213.217.0.133 DST=195.201.40.59 LEN=40 TOS=0x00 PREC=0x00 TTL=245 ID=33759 PROTO=TCP SPT=43933 DPT=59822 WINDOW=1024 RES=0x00 SYN URGP=0

May  7 07:18:47 sxvn sshd[634811]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=187.134.163.223

Rude login attack (583 tries in 1d)

May  7 05:55:38 debian-2gb-nbg1-2 kernel: \[11082625.336037\] \[UFW BLOCK\] IN=eth0 OUT= MAC=96:00:00:0e:18:f4:d2:74:7f:6e:37:e3:08:00 SRC=39.105.94.150 DST=195.201.40.59 LEN=40 TOS=0x00 PREC=0x00 TTL=237 ID=30008 PROTO=TCP SPT=58950 DPT=17740 WINDOW=1024 RES=0x00 SYN URGP=0

$f2bV_matches

Unauthorized connection attempt detected from IP address 222.186.42.136 to port 22

[2020-05-07 01:40:21] NOTICE[1157] chan_sip.c: Registration from '' failed for '185.147.215.8:59195' - Wrong password
[2020-05-07 01:40:21] SECURITY[1173] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-05-07T01:40:21.137-0400",Severity="Error",Service="SIP",EventVersion="2",AccountID="3652",SessionID="0x7f5f1011fc08",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/185.147.215.8/59195",Challenge="7a70c4da",ReceivedChallenge="7a70c4da",ReceivedHash="2b99b47bef90a03b14109b50ac018630"
[2020-05-07 01:40:34] NOTICE[1157] chan_sip.c: Registration from '' failed for '185.147.215.8:51908' - Wrong password
[2020-05-07 01:40:34] SECURITY[1173] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-05-07T01:40:34.199-0400",Severity="Error",Service="SIP",EventVersion="2",AccountID="572",SessionID="0x7f5f10518f48",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/185.147.215.8/5
...

Cowrie Honeypot: Unauthorised SSH/Telnet login attempt with user "admin" at 2020-05-07T05:52:30Z

Brute forcing RDP port 3389

Triggered by Fail2Ban at Ares web server