[2020-09-26 23:25:46] NOTICE[1159][C-00002376] chan_sip.c: Call from '' (37.49.230.87:51231) to extension '900940441904911032' rejected because extension not found in context 'public'.
[2020-09-26 23:25:46] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-26T23:25:46.655-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="900940441904911032",SessionID="0x7fcaa00dd368",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/37.49.230.87/51231",ACLName="no_extension_match"
[2020-09-26 23:26:25] NOTICE[1159][C-00002377] chan_sip.c: Call from '' (37.49.230.87:54479) to extension '900941441904911032' rejected because extension not found in context 'public'.
[2020-09-26 23:26:25] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-26T23:26:25.135-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="900941441904911032",SessionID="0x7fcaa00dd368",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="
...

[2020-09-26 23:25:46] NOTICE[1159][C-00002376] chan_sip.c: Call from '' (37.49.230.87:51231) to extension '900940441904911032' rejected because extension not found in context 'public'.
[2020-09-26 23:25:46] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-26T23:25:46.655-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="900940441904911032",SessionID="0x7fcaa00dd368",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/37.49.230.87/51231",ACLName="no_extension_match"
[2020-09-26 23:26:25] NOTICE[1159][C-00002377] chan_sip.c: Call from '' (37.49.230.87:54479) to extension '900941441904911032' rejected because extension not found in context 'public'.
[2020-09-26 23:26:25] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-26T23:26:25.135-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="900941441904911032",SessionID="0x7fcaa00dd368",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="
...

 TCP (SYN) 37.49.230.87:40229 -> port 22, len 40

Bible

2020-10-13T06:44:21.356144news0 auth[956]: pam_unix(dovecot:auth): authentication failure; logname= uid=0 euid=0 tty=dovecot ruser=admin rhost=37.49.230.238
2020-10-13T06:44:25.395781news0 dovecot[21131]: pop3-login: Aborted login (auth failed, 1 attempts in 4 secs): user=, method=PLAIN, rip=37.49.230.238, lip=95.111.246.42, session=
2020-10-13T06:44:28.401407news0 auth[956]: pam_unix(dovecot:auth): authentication failure; logname= uid=0 euid=0 tty=dovecot ruser=admin rhost=37.49.230.238
...

2020-10-13T06:44:21.356144news0 auth[956]: pam_unix(dovecot:auth): authentication failure; logname= uid=0 euid=0 tty=dovecot ruser=admin rhost=37.49.230.238
2020-10-13T06:44:25.395781news0 dovecot[21131]: pop3-login: Aborted login (auth failed, 1 attempts in 4 secs): user=, method=PLAIN, rip=37.49.230.238, lip=95.111.246.42, session=
2020-10-13T06:44:28.401407news0 auth[956]: pam_unix(dovecot:auth): authentication failure; logname= uid=0 euid=0 tty=dovecot ruser=admin rhost=37.49.230.238
...

Dovecot Invalid User Login Attempt.

"AmooT";tag=3533393765393339313363340132313832313335333935

\[2020-10-02 15:01:13\] SECURITY\[6939\] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-10-02T15:01:13.624+0200",Severity="Error",Service="SIP",EventVersion="2",AccountID="100",SessionID="0x7f0ffea08d88",LocalAddress="IPV4/UDP/204.8.216.89/5060",RemoteAddress="IPV4/UDP/37.49.230.126/5862",Challenge="096f171f",ReceivedChallenge="096f171f",ReceivedHash="b099bdfad5869da4ae2114a56a2b4299"
\[2020-10-02 15:01:13\] SECURITY\[6939\] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-10-02T15:01:13.759+0200",Severity="Error",Service="SIP",EventVersion="2",AccountID="100",SessionID="0x7f0ffeab8148",LocalAddress="IPV4/UDP/204.8.216.89/5060",RemoteAddress="IPV4/UDP/37.49.230.126/5862",Challenge="233a417c",ReceivedChallenge="233a417c",ReceivedHash="0017581d14759d4b5ad3a404ed924131"
\[2020-10-02 15:01:13\] SECURITY\[6939\] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-10-02T15:01:13.783+0200",Severity="Error",Service="SIP",EventVersion="2",Accoun
...

\[2020-10-02 15:01:13\] SECURITY\[6939\] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-10-02T15:01:13.624+0200",Severity="Error",Service="SIP",EventVersion="2",AccountID="100",SessionID="0x7f0ffea08d88",LocalAddress="IPV4/UDP/204.8.216.89/5060",RemoteAddress="IPV4/UDP/37.49.230.126/5862",Challenge="096f171f",ReceivedChallenge="096f171f",ReceivedHash="b099bdfad5869da4ae2114a56a2b4299"
\[2020-10-02 15:01:13\] SECURITY\[6939\] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-10-02T15:01:13.759+0200",Severity="Error",Service="SIP",EventVersion="2",AccountID="100",SessionID="0x7f0ffeab8148",LocalAddress="IPV4/UDP/204.8.216.89/5060",RemoteAddress="IPV4/UDP/37.49.230.126/5862",Challenge="233a417c",ReceivedChallenge="233a417c",ReceivedHash="0017581d14759d4b5ad3a404ed924131"
\[2020-10-02 15:01:13\] SECURITY\[6939\] res_security_log.c: SecurityEvent="InvalidPassword",EventTV="2020-10-02T15:01:13.783+0200",Severity="Error",Service="SIP",EventVersion="2",Accoun
...

[N1.H1.VM1] Port Scanner Detected Blocked by UFW

SIP Server BruteForce Attack

[2020-09-30 18:00:12] NOTICE[1159][C-0000421d] chan_sip.c: Call from '' (37.49.230.201:64644) to extension '12526890745' rejected because extension not found in context 'public'.
[2020-09-30 18:00:12] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-30T18:00:12.866-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="12526890745",SessionID="0x7fcaa045f8f8",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/37.49.230.201/64644",ACLName="no_extension_match"
[2020-09-30 18:00:26] NOTICE[1159][C-0000421f] chan_sip.c: Call from '' (37.49.230.201:57391) to extension '712526890745' rejected because extension not found in context 'public'.
[2020-09-30 18:00:26] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-30T18:00:26.237-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="712526890745",SessionID="0x7fcaa04d8d08",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/37.49.230.201/
...

[2020-09-30 18:00:12] NOTICE[1159][C-0000421d] chan_sip.c: Call from '' (37.49.230.201:64644) to extension '12526890745' rejected because extension not found in context 'public'.
[2020-09-30 18:00:12] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-30T18:00:12.866-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="12526890745",SessionID="0x7fcaa045f8f8",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/37.49.230.201/64644",ACLName="no_extension_match"
[2020-09-30 18:00:26] NOTICE[1159][C-0000421f] chan_sip.c: Call from '' (37.49.230.201:57391) to extension '712526890745' rejected because extension not found in context 'public'.
[2020-09-30 18:00:26] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-30T18:00:26.237-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="712526890745",SessionID="0x7fcaa04d8d08",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/37.49.230.201/
...

[2020-09-30 18:00:12] NOTICE[1159][C-0000421d] chan_sip.c: Call from '' (37.49.230.201:64644) to extension '12526890745' rejected because extension not found in context 'public'.
[2020-09-30 18:00:12] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-30T18:00:12.866-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="12526890745",SessionID="0x7fcaa045f8f8",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/37.49.230.201/64644",ACLName="no_extension_match"
[2020-09-30 18:00:26] NOTICE[1159][C-0000421f] chan_sip.c: Call from '' (37.49.230.201:57391) to extension '712526890745' rejected because extension not found in context 'public'.
[2020-09-30 18:00:26] SECURITY[1198] res_security_log.c: SecurityEvent="FailedACL",EventTV="2020-09-30T18:00:26.237-0400",Severity="Error",Service="SIP",EventVersion="1",AccountID="712526890745",SessionID="0x7fcaa04d8d08",LocalAddress="IPV4/UDP/192.168.244.6/5060",RemoteAddress="IPV4/UDP/37.49.230.201/
...

Hellooo

Hellooo

Sep 28 15:49:19 : SSH login attempts with invalid user

 TCP (SYN) 103.141.234.41:58465 -> port 445, len 48

 TCP (SYN) 92.63.197.55:47298 -> port 4689, len 44

detected by Fail2Ban

Jun 10 05:42:04 relay postfix/smtpd\[11169\]: warning: unknown\[193.56.28.208\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Jun 10 05:42:27 relay postfix/smtpd\[11169\]: warning: unknown\[193.56.28.208\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Jun 10 05:42:38 relay postfix/smtpd\[11169\]: warning: unknown\[193.56.28.208\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Jun 10 05:43:46 relay postfix/smtpd\[11169\]: warning: unknown\[193.56.28.208\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Jun 10 05:53:00 relay postfix/smtpd\[14894\]: warning: unknown\[193.56.28.208\]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
...

no

2020-06-10T07:36:49.682831vps751288.ovh.net sshd\[23988\]: Invalid user test from 132.232.66.238 port 59370
2020-06-10T07:36:49.690134vps751288.ovh.net sshd\[23988\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=132.232.66.238
2020-06-10T07:36:51.657105vps751288.ovh.net sshd\[23988\]: Failed password for invalid user test from 132.232.66.238 port 59370 ssh2
2020-06-10T07:41:31.880351vps751288.ovh.net sshd\[24029\]: Invalid user www-admin from 132.232.66.238 port 60382
2020-06-10T07:41:31.888221vps751288.ovh.net sshd\[24029\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=132.232.66.238

"Unauthorized connection attempt on SSHD detected"

Jun 10 05:46:19 ns392434 sshd[19926]: Invalid user jason from 123.30.149.76 port 46042
Jun 10 05:46:19 ns392434 sshd[19926]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=123.30.149.76
Jun 10 05:46:19 ns392434 sshd[19926]: Invalid user jason from 123.30.149.76 port 46042
Jun 10 05:46:21 ns392434 sshd[19926]: Failed password for invalid user jason from 123.30.149.76 port 46042 ssh2
Jun 10 06:00:40 ns392434 sshd[20179]: Invalid user kapaul from 123.30.149.76 port 42461
Jun 10 06:00:40 ns392434 sshd[20179]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=123.30.149.76
Jun 10 06:00:40 ns392434 sshd[20179]: Invalid user kapaul from 123.30.149.76 port 42461
Jun 10 06:00:42 ns392434 sshd[20179]: Failed password for invalid user kapaul from 123.30.149.76 port 42461 ssh2
Jun 10 06:04:29 ns392434 sshd[20303]: Invalid user test from 123.30.149.76 port 43159

SSH Scan

Port scan - 6 hits (greater than 5)

Jun 10 04:52:34 l02a sshd[17810]: Invalid user zhongjunquan from 51.91.100.109
Jun 10 04:52:34 l02a sshd[17810]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=109.ip-51-91-100.eu 
Jun 10 04:52:34 l02a sshd[17810]: Invalid user zhongjunquan from 51.91.100.109
Jun 10 04:52:36 l02a sshd[17810]: Failed password for invalid user zhongjunquan from 51.91.100.109 port 55076 ssh2

(mod_security) mod_security (id:210492) triggered by 1.84.29.62 (CN/China/-): 5 in the last 3600 secs

Jun 10 09:01:28 lukav-desktop sshd\[8372\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=171.244.139.142  user=root
Jun 10 09:01:29 lukav-desktop sshd\[8372\]: Failed password for root from 171.244.139.142 port 46468 ssh2
Jun 10 09:03:16 lukav-desktop sshd\[8404\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=171.244.139.142  user=root
Jun 10 09:03:18 lukav-desktop sshd\[8404\]: Failed password for root from 171.244.139.142 port 42232 ssh2
Jun 10 09:05:06 lukav-desktop sshd\[10364\]: pam_unix\(sshd:auth\): authentication failure\; logname= uid=0 euid=0 tty=ssh ruser= rhost=171.244.139.142  user=root

2020-06-10T07:25:19.054712n23.at sshd[30092]: Failed password for root from 62.197.252.82 port 25807 ssh2
2020-06-10T07:26:30.908242n23.at sshd[31173]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=62.197.252.82  user=root
2020-06-10T07:26:33.231613n23.at sshd[31173]: Failed password for root from 62.197.252.82 port 42710 ssh2
...

Jun  9 23:52:38 Tower sshd[32120]: Connection from 111.93.10.213 port 45698 on 192.168.10.220 port 22 rdomain ""
Jun  9 23:52:40 Tower sshd[32120]: Invalid user simran from 111.93.10.213 port 45698
Jun  9 23:52:40 Tower sshd[32120]: error: Could not get shadow information for NOUSER
Jun  9 23:52:40 Tower sshd[32120]: Failed password for invalid user simran from 111.93.10.213 port 45698 ssh2
Jun  9 23:52:40 Tower sshd[32120]: Received disconnect from 111.93.10.213 port 45698:11: Bye Bye [preauth]
Jun  9 23:52:40 Tower sshd[32120]: Disconnected from invalid user simran 111.93.10.213 port 45698 [preauth]