Jan  1 07:29:39 debian-2gb-nbg1-2 kernel: \[119512.334201\] \[UFW BLOCK\] IN=eth0 OUT= MAC=96:00:00:0e:18:f4:d2:74:7f:6e:37:e3:08:00 SRC=119.247.17.87 DST=195.201.40.59 LEN=40 TOS=0x00 PREC=0x00 TTL=53 ID=18944 PROTO=TCP SPT=42447 DPT=5555 WINDOW=46172 RES=0x00 SYN URGP=0 
Jan  1 07:29:39 debian-2gb-nbg1-2 kernel: \[119512.354480\] \[UFW BLOCK\] IN=eth0 OUT= MAC=96:00:00:0e:18:f4:d2:74:7f:6e:37:e3:08:00 SRC=119.247.17.87 DST=195.201.40.59 LEN=40 TOS=0x00 PREC=0x00 TTL=53 ID=63960 PROTO=TCP SPT=42447 DPT=5555 WINDOW=46172 RES=0x00 SYN URGP=0

Jan  1 07:29:23 * sshd[8863]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=106.13.28.16
Jan  1 07:29:25 * sshd[8863]: Failed password for invalid user dud from 106.13.28.16 port 58188 ssh2

[portscan] Port scan

Unauthorized connection attempt detected from IP address 120.214.165.190 to port 23

Jan  1 07:29:38 vpn01 sshd[23522]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=187.87.39.147
Jan  1 07:29:40 vpn01 sshd[23522]: Failed password for invalid user softball from 187.87.39.147 port 58140 ssh2
...

Jan  1 05:59:16 raspberrypi sshd\[15526\]: Invalid user info from 129.204.11.222Jan  1 05:59:18 raspberrypi sshd\[15526\]: Failed password for invalid user info from 129.204.11.222 port 40538 ssh2Jan  1 06:29:38 raspberrypi sshd\[16593\]: Invalid user karstein from 129.204.11.222
...

Jan  1 06:29:44 internal-server-tf sshd\[31302\]: Invalid user oracle from 199.19.224.191Jan  1 06:29:44 internal-server-tf sshd\[31297\]: Invalid user aws from 199.19.224.191Jan  1 06:29:44 internal-server-tf sshd\[31304\]: Invalid user tomcat from 199.19.224.191
...

Port Scan

2020-01-01T06:26:37.590196abusebot-4.cloudsearch.cf sshd[8734]: Invalid user causley from 106.75.15.142 port 59984
2020-01-01T06:26:37.599700abusebot-4.cloudsearch.cf sshd[8734]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=106.75.15.142
2020-01-01T06:26:37.590196abusebot-4.cloudsearch.cf sshd[8734]: Invalid user causley from 106.75.15.142 port 59984
2020-01-01T06:26:39.785841abusebot-4.cloudsearch.cf sshd[8734]: Failed password for invalid user causley from 106.75.15.142 port 59984 ssh2
2020-01-01T06:29:35.656652abusebot-4.cloudsearch.cf sshd[8886]: Invalid user server from 106.75.15.142 port 47454
2020-01-01T06:29:35.662181abusebot-4.cloudsearch.cf sshd[8886]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=106.75.15.142
2020-01-01T06:29:35.656652abusebot-4.cloudsearch.cf sshd[8886]: Invalid user server from 106.75.15.142 port 47454
2020-01-01T06:29:37.286100abusebot-4.cloudsearch.cf sshd[8886]: Failed
...

Tried sshing with brute force.

Jan  1 07:29:29 grey postfix/smtpd\[27049\]: NOQUEUE: reject: RCPT from strapped.vidyad.com\[63.81.87.110\]: 554 5.7.1 Service unavailable\; Client host \[63.81.87.110\] blocked using truncate.gbudb.net\; http://www.gbudb.com/truncate/ \[63.81.87.110\]\; from=\ to=\ proto=ESMTP helo=\Jan  1 07:29:29 grey postfix/smtpd\[21908\]: NOQUEUE: reject: RCPT from strapped.vidyad.com\[63.81.87.110\]: 554 5.7.1 Service unavailable\; Client host \[63.81.87.110\] blocked using truncate.gbudb.net\; http://www.gbudb.com/truncate/ \[63.81.87.110\]\; from=\ to=\ proto=ESMTP helo=\
...

\[2020-01-01 01:51:22\] NOTICE\[2839\] chan_sip.c: Registration from '\' failed for '195.154.28.229:57499' - Wrong password
\[2020-01-01 01:51:22\] SECURITY\[2857\] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-01-01T01:51:22.585-0500",Severity="Error",Service="SIP",EventVersion="2",AccountID="4007",SessionID="0x7f0fb4aabfc8",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/195.154.28.229/57499",Challenge="74e91532",ReceivedChallenge="74e91532",ReceivedHash="65bcacd36d88d5e9fb015765061d4d68"
\[2020-01-01 01:52:01\] NOTICE\[2839\] chan_sip.c: Registration from '\' failed for '195.154.28.229:64317' - Wrong password
\[2020-01-01 01:52:01\] SECURITY\[2857\] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-01-01T01:52:01.770-0500",Severity="Error",Service="SIP",EventVersion="2",AccountID="4008",SessionID="0x7f0fb41946f8",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/195.15

2020-01-01T07:08:35.234788shield sshd\[22116\]: Invalid user freusen from 104.200.144.166 port 34482
2020-01-01T07:08:35.239076shield sshd\[22116\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=104.200.144.166
2020-01-01T07:08:37.103556shield sshd\[22116\]: Failed password for invalid user freusen from 104.200.144.166 port 34482 ssh2
2020-01-01T07:11:03.942293shield sshd\[23017\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=104.200.144.166  user=root
2020-01-01T07:11:05.455850shield sshd\[23017\]: Failed password for root from 104.200.144.166 port 33920 ssh2

\[2020-01-01 01:49:24\] SECURITY\[2857\] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-01-01T01:49:24.734-0500",Severity="Error",Service="SIP",EventVersion="1",AccountID="01146812111747",SessionID="0x7f0fb4aabfc8",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/185.53.88.3/59816",ACLName="no_extension_match"
\[2020-01-01 01:49:27\] SECURITY\[2857\] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-01-01T01:49:27.558-0500",Severity="Error",Service="SIP",EventVersion="1",AccountID="011442037694876",SessionID="0x7f0fb42932b8",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/185.53.88.3/57084",ACLName="no_extension_match"
\[2020-01-01 01:49:40\] SECURITY\[2857\] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-01-01T01:49:40.662-0500",Severity="Error",Service="SIP",EventVersion="1",AccountID="01146812111747",SessionID="0x7f0fb41946f8",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/185.53.88.3/52058",ACLName="no_extension_m

01/01/2020-08:05:03.011762 198.211.120.59 Protocol: 17 ET INFO Session Traversal Utilities for NAT (STUN Binding Response)